The Lentil Soup That Doesn’t Taste Like a Health Decision

Lentils can be compared to a certain personality type; they present themselves as “fun” and “interesting”, but really, the only time you would want to be around them is for brunch. Rather, lentils are brown, wet, and wholesome. And, to make it worse, someone who you have the most disdain for will suggest it to you. Lentils seem to have a huge reputation problem, but it’s not their fault. You are, quite literally, just eating lentils that are made by people who didn’t believe in them.

This recipe shows the power of paprika and orange peel. These two ingredients give the broth an almost indescribable warmth that people will notice when it is missing. A lot of people don’t add a tablespoon of red wine vinegar, but that changes lentil porridge to lentil soup.

Then, to convert the bowl into a dialogue, take a spoonful of quick-pickled red onions that are sliced thin and vinegared while the soup simmers. That last touch is what makes this “great lentil soup” to “wait, what’s in this?”

The Quick Rundown

• The heart of it: A weeknight lentil soup based on mirepoix, with some additional smoked paprika and cumin, tomatoes, lentils, a bay leaf plus a strip of orange peel; finished with red wine vinegar and quick-pickled red onions.
• Why it works: The broth is given an aromatic depth that is hard to qualify and describe with the combination of smoked paprika and orange peel. The addition of vinegar at the end provides a bright note that takes it from “muddy” to “done.” Finally, pickled red onions bring in color, crunch, and their own pop of acidity right at the top.
• Timing: It will take approximately 10 minutes to prep the recipe, and around 35 to 40 minutes to cook it. Be sure to start the pickled onions before the soup because they will be ready right when you need to serve it. This recipe serves 4 people generously.
• Flavor profile: The dish has smoky and savory flavors, and also has a gentle sweetness from the carrots and onions. The citrus and warmth come from the orange peel, and there is a nice brightness from the vinegar. The dish is peppery at the finish and has a nice sharp crunch from the fried onion pieces on top.
• Key tips: Start with the pickled onions. It’s important to include the smoked paprika as well as the orange peel, and finishing vinegar should also be included. Check the lentils for pebbles before they go into the pot.

Ingredients

Each of the three components will be given its own paragraph here. The first one is smoked paprika, which is different from regular paprika and is required. The soup tastes like more than just wet legumes because of this. The best $4 value in the entire spice cabinet has a small jar that lasts a year.

The second is a strip of orange peel, placed in with the bay leaf and removed before serving. With this Spanish/Provençal move that few people make with lentil soup, you can transform your soup from an ordinary pot to a destination-worthy one. Using a vegetable peeler, make a 2-inch ribbon from a standard orange (try to avoid the white pith as much as possible).

The third is vinegar: red wine vinegar is used twice, once in the soup at the end, and once as the brine for the pickled red onion topping. The addition of balsamic is also an option. For example, without acid at the end, the soup tastes muddy. However, pickled onions are the ones who change a brown bowl into something you actually want to take a picture of.

• Olive oil (2 tbsp): Or any neutral oil.
• Yellow or white onion (1 large, chopped): The base of the mirepoix.
• Carrots (2 medium, diced): Cut them to approximately the same size as the celery so they cook at the same rate.
• Celery (2 stalks, diced): Equal parts with the onion and carrot.
• Garlic (3 cloves, minced): It goes in with the spices, not the mirepoix, because the longer cooking time will cause it to scorch.
• Cumin (1 tsp): Ground; bloomed in the oil.
• Smoked paprika (1 tsp): The sweet variety is more versatile, but both sweet and hot smoked work.
• Green or brown lentils (1 cup): If you have them, French Le Puy lentils are the upgrade as they hold their shape better.
• Canned diced tomatoes (1 x 14 oz, with juice): If you have them, fire-roasted is a small additional charge.
• Broth (4 cups): Vegetable and chicken options are available. Low sodium so you can add your own salt.
• Bay leaf (1): Background warmth; pulled out before serving.
• Strip of orange peel (1, about 2 inches): The white pith has been removed from the orange and has been peeled as if from a regular orange. It is added with the bay leaf and removed before serving.
• Spinach or kale (a couple of handfuls): Added at the very end; collapses fast.
• Red wine vinegar (1 tbsp for the soup, plus 1/4 cup for the pickled onions): Balsamic vinegar is what changes this dish from porridge to soup, and is also a suitable option for the finish.
• Freshly cracked black pepper: Generous. Lentils love pepper.
• Kosher salt: At the end you might want to taste the broth and tomatoes as they contain their own salt.
• Optional Parmesan rind: Add it to the lentils while cooking, and remove it before serving. It’ll add a subtle savory flavor.

For The Quick-Pickled Red Onions

Make these first. They take about 20 minutes to prepare and only get better as the soup simmers. A double batch can be stored in the fridge for 1-2 weeks and it improves sandwiches, tacos, eggs, salads and grain bowls.

• Red onion (1/2 small): Cut into the thinnest slices you can, preferably using a mandoline, but a good knife will work as well.
• Red wine vinegar (about 1/4 cup): Sufficient to mostly conceal the onions in a small bowl or jar.
• Kosher salt (a pinch):
• Sugar (a pinch): Softens the harshness without adding sweetness.

Master Ratio (Easy To Scale)

• Per 1 cup dry lentils (serves 4): 1 onion; 2 carrots; 2 stalks of celery; 3 cloves of garlic; 1 can of tomatoes; 4 cups of broth; 1 strip of orange peel; 1 tbsp of vinegar (for finishing)
• Spice ratio: Use approximately 1 teaspoon of ground spices for every 1 cup of dry lentils. If you prefer a stronger smoky flavor, you can double the amount of smoked paprika.
• Pickled onion topping (tops 4 bowls): Combine 1/2 of a small red onion, a 1/4 cup of red wine vinegar, and a pinch of salt and a pinch of sugar.

Sample: Would it be all right to double the batch for a larger pot or to have extra leftovers? Instead of one pot being crowded, run two pots side by side.

Two cups of lentils will require more broth than anticipated (closer to 7 cups is better than 8), and to get the best texture, it’s best to have space to simmer. A double batch isn’t a waste as this soup lasts 4 days, it just needs the space. For sure double the pickled onions. They last a week or two, and you’ll want to have some on hand.

Ingredient Choices That Change Flavor

Instructions

You will need a 4-quart or larger pot such as a Dutch oven or another heavy-bottom pot. Heavy-bottomed pots are critical because thin-bottomed pots burn the bottom layer of the soup as it thickens. Make the pickled onions ahead of time as you will need them when the soup is ready to serve.

1) Start the pickled red onions. Slice the small red onion as thinly as you can and deposit the pieces into a small bowl or jar. Add about 1/4 cup of red wine vinegar to the bowl so that it mostly covers the pieces.

Put in a pinch of kosher salt and a pinch of sugar, and stir. Simply place them on the counter and leave them. Once the soup is finished, they will be ready for you to scoop and add that hot pink crunch on top.

2) Begin working on the mirepoix. Use a Dutch oven or large pot to heat 2 tablespoons of olive oil over medium heat.

Add roughly chopped onion, diced carrots (2), diced celery stalks (2). Make sure they are equal parts and cut to roughly the same dimensions so they cook evenly.

Cook for 8 minutes, stirring occasionally, until the onion becomes translucent and the carrots soften. This step may seem repetitive, but if done too quickly it will result in your soup tasting like celery water.

 

3) Add the garlic and bloom the spices. For this, you will need 3 minced cloves of garlic, 1 tsp. of cumin, and 1 tsp. of smoked paprika. Cook for 30 seconds while stirring. You should start to notice the aroma of a real dinner beginning to fill the space. Smoked paprika is the secret weapon here. Unlike regular paprika, it adds a much greater depth of flavor.

4) Add the lentils and orange peel, then let it simmer. Toss in 1 cup of rinsed green or brown lentils (rinse them and check for pebbles), a 14-oz can of diced tomatoes, and 4 cups of broth along with a bay leaf and a 2-inch strip of orange peel. Orange peel in lentil soup is the kind of thing 95% of the people won’t do but it adds the same kind of warm, aromatic, and slightly mysterious depth to the broth that the smoked paprika does to the spice base.

Once everything is in, bring the soup to a simmer. Cover the pot and cook it for 25-30 minutes or until the lentils are tender but still a little firm. Red lentils can be used as a substitute. They will only take 15 minutes to cook but will break down to create a thicker, porridge-like soup, which can be nice. A Parmesan rind adds depth to the soup but makes the flavor more from the background. Just remember to take the rind, bay leaf, and orange peel out before serving.

5) To finish the dish, wilt the greens, and serve with the onions on top. During the last two minutes of cooking, add a few handfuls of spinach so that they wilt, and then (this is the step most people forget to do) add a splash of red wine vinegar or balsamic (about a tablespoon) and a generous amount of freshly cracked black pepper.

It’s the vinegar that gives the soup a balanced taste; without it, you’ve got lentil porridge, but with it, you’ve got soup. Adjust the seasoning as necessary.

6) Serve the soup into bowls, top with a generous spoonful of pickled red onions (including a little of the pink brine) and serve immediately. For a touch of heat, smokiness, and a bit of brightness, I recommend adding a spoonful of harissa stirred in right before serving.

Variations Worth Trying

• Add Italian sausage: Brown 8 oz of crumbled sweet or hot Italian sausage in the pot first, set aside, then build the mirepoix in the rendered fat. Return the sausage with the lentils.
• Bacon-forward: Prepare 4 strips of chopped bacon before proceeding to the mirepoix; you may want to reduce the amount of olive oil. The smoke works wonderfully in combination with the smoked paprika.
• Coconut-cumin version: Replace the cumin with 1 tsp of curry powder and finish with 1/2 cup of coconut milk before adding the vinegar. This will pivot the dish to South Asian cuisine, so serve it with rice or naan. (Leave out the orange peel; it competes with the coconut.)
• Lemon peel + lemon finish: Exchange the orange peel for a 2-inch strip of lemon peel, and finish with a squeeze of lemon rather than vinegar. This will make the dish brighter and more citrusy, and it especially pairs well with kale.
• Red lentil porridge version: If using red lentils instead of green, cook for 15-20 minutes. The soup will break down into a silky thick stew. Less “soup” more “bowl.”
• Greens swap: If you want a hardier green, Lacinato kale (chopped and with stems removed) holds up better than spinach. Add in the last 5 minutes, instead of 2.
• Spicier version: Incorporate a diced fresh chili along with some garlic, or if you choose, you may add a dash of crushed red chili along with the other spices. Additionally, a spoonful of harissa is also an option to add at the end.
• Pickled onion variations: Choose one of the following to add to the brine: Some coriander seeds, a clove of crushed garlic, or a piece of orange peel.

What Goes Alongside

• Crusty bread with butter: A good bread roll is unforgivable without including a chilled knob of salted butter.
• Grilled cheese on the side: A grilled cheese with sharp cheddar on sturdy bread, made for dunking.
• A sharp salad: The bitterness juxtaposes with the smoky depth of the soup. Arugula, shaved fennel, a squeeze of lemon, olive oil, flaky salt.
• Greek yogurt or sour cream dollop: A spoonful in the bowl tones down the smoke and provides a little lift that goes nicely with the vinegar and the pickled onions.
• A glass of light red: Avoid heavy oaky reds. Chianti, young Tempranillo, and Beaujolais can be good options.
• Build-your-bowl move: Place the pickled onions, a small bowl of chopped dill or parsley, a wedge of lemon, and good olive oil on the table. Guests can customize their bowls however they like. That’s restaurant quality in 30 seconds!

Fixes and Pro Moves

• The lentils are still firm after 30 minutes: Lentils that are more than one year old tend to take longer to cook. Continue simmering the lentils, and add more broth if the soup is getting too thick. Check the lentils every ten minutes as more than one year old lentils will take longer to cook. If the broth is acidic (contains a lot of tomato), the cooking time may be even longer.
• The soup tastes muddy or one-note: Most of the time this requires adding vinegar. It is just a guess measurement so start with a tablespoon and see if this is correct. Give it a stir and then taste it again. If it remains flat, the next instructions are to add some salt and pepper. If it is still flat after this, consider adding a small spoonful of hot sauce or harissa, as this often unlocks it.
• The orange peel made the broth bitter: There is excessive white pith on the strip. Next time, use a vegetable peeler instead of a knife and target just the color layer. If it’s already in the pot, remove the peel early and taste; the bitterness is usually mild and goes away with the vinegar finish.
• The pickled onions taste harsh: It will take at least twenty minutes for them to transform. The more time they spend sitting in the brine, the rounder they will become. A little bit more sugar helps as well. If they are still too sharp, drain most of the brine, and add a small amount of water.
• The soup is too thick: Add more broth or water and a little vinegar to preserve the ratio. As the soup sits, lentils will continue to absorb liquid.
• The soup is too thin: Leave uncovered for another 10 minutes so that the lentils can release even more starches to thicken the soup. You may also blend a cup of the soup and stir the blended soup back into the pot to add more body to it.
• The bottom of the pot is scorching: Use a heavy bottomed pot and lower the heat. Stir more frequently as the soup thickens. If you’ve burned the bottom, transfer the soup (without scraping the bottom) to a different pot and rescue what’s above the burn line.
• The carrots are still crunchy: You may have either cut them too large, or you rushed the mirepoix step, next time try smaller dice; make sure to sweat for a full 8 minutes before adding the spices.
• The smoked paprika is making it taste medicinal: Many people overlook the importance of quality. For example, old and cheap smoked paprika can taste off-putting. Reasonably priced and freshly sealed jars from reputable spice companies can make a large difference.

How It Keeps

It is rare to find a dish that is both healthy and enjoyable, but you can say that about Lentil Soup. Although some versions of this soup may have bacon or sausage, the soup is generally low in fat. The lentils and vegetables contain a good amount of plant protein, fiber, and healthy fats.

The pickled onion topping is almost calorie-free and adds an acidic kick that promotes fullness. The only health concern is sodium, so use low-sodium broth and don’t overdo the seasoning at the end. If you are looking for a more filling dinner, adding a splash of olive oil and a piece of bread will be more satisfying than just throwing in more lentils.

You can keep soup leftovers in an airtight container in the refrigerator for up to 4 days. If you wish to reheat the soup, please do so gently on the stovetop and add a little broth or water to the pot before reheating the soup. Keep in mind that the lentils will absorb the liquid and will cause the soup to thicken overnight. Freshly squeeze some vinegar or lemon into the soup right before you reheat it.

After a day in the fridge, the acid will dull so it is better to add it before reheating the soup. The soup will freeze well for three months, to defrost it, place it in the fridge overnight. Pickled onions will last for 1 to 2 weeks in their brine in a sealed jar so keep that in mind if you plan to use them! The pickled onions are a great addition to sandwiches, tacos, eggs, salads, and grain bowls, so a double batch is rarely wasted.

Kitchen Stories

Example 1 (the polite skeptic): In our family, we know that my older brother would “pass” on eating lentils by nodding at my mum when she mentioned them. I made this soup the other weekend when he came to visit. I served him a bowl without saying anything.

He took a spoonful and asked, in what sounded to me like he was being suspicious of something he wasn’t expecting to like, what it was. I said lentils. He stopped, and looked at the bowl like it had done something to him, and then he actually went for more. It was the onions on top that made him stop pretending.

Example 2 (the vinegar epiphany): When I first made this soup, vinegar was absent from the ingredient list. While eating her bowl, a friend asked, “Do you have any vinegar in the kitchen?” I remember thinking it was clever, and it’s stuck with me ever since. Vinegar isn’t merely a display ingredient; it’s an active player. The other soup ingredients have been waiting for it. The pickled onions came in later after I found I could have acid and texture in one spoon.

The Checklist

• Pantry check: olive oil, onion, carrots, celery, garlic, cumin, smoked paprika, lentils, canned diced tomatoes, broth, bay leaf, an orange, spinach (or kale), red wine vinegar, red onion, salt, sugar, pepper.
• Start the pickled onions first. Cut the half red onion into thin slices, and combine the red onion slices with a quarter cup of red wine vinegar, a pinch of salt, and a pinch of sugar. Let this mixture sit on the counter.
• Dice the mirepoix small and even.
• Take your time to sweat the mirepoix for a full 8 minutes.
• Add garlic and spices then stir for 30 seconds (set a timer).
• Add rinsed lentils, tomatoes, broth, bay leaf, and a 2-inch strip of orange peel. Optional Parmesan rind.
• Cover and simmer for 25 to 30 minutes or until the lentils are tender.
• Add the spinach and stir for 2 more minutes.
• Remove the bay leaf and orange peel.
• Complete with vinegar and cracked pepper. Taste and adjust the salt.
• Ladle into bowls. Top each one with a generous spoonful of pickled red onions.

Terms Worth Knowing

• Mirepoix: The French aromatic base consists of onions, carrots and celery (usually in a ratio of 2:1:1). The vegetables are sweated slowly to form the foundation for soups, stews and braises.
• Sweating (vs. sautéing): Cooking vegetables over a medium-low flame is chewy without generating color on the vegetables. This is gentler than sautéing or browning.
• Blooming spices: Cooking dry spices in hot fat releases their fat-soluble flavor compounds, which typically happens in about thirty seconds.
• Smoked paprika: Spanish paprika (pimentón) is produced from smoked peppers, ground over oak. They offer a sweet (dulce) and a hot (picante) version. It is never to be confused with ordinary paprika.
• Quick pickle: A short-soak pickle (20 minutes up to a few hours) involves soaking cucumbers in a solution of vinegar, salt, and possibly sugar. Pickles of this type are more crunchy and bright than long-fermented pickles, and are ready in the amount of time it takes to prepare the rest of the meal.
• Citrus peel as aromatic: In many lentil soup recipes, you won’t find any citrus peel, which is an ingredient used to perfume a simmer. For the most part, citrus peel consists of the bright orange or lemon rind that is free of the bitter white pith. It is a common ingredient in many Provençal and Spanish cuisines.
• Parmesan rind: Parmesan cheese comes with a hard outer crust that most people throw away. However, it is a great addition for enhancing soups and stocks. Just simmer it in the broth and be sure to remove it before serving.
• Le Puy lentils: They are small, dark green and have an assertive (peppery) flavor and a firm texture, which provide their premium quality. They also hold their shape during cooking exceptionally well.
• Finishing acid: When cooking over a long period of time, flavors can become flat or muddy. A splash of vinegar or a citrus juice added at the end of cooking can brighten these flavors.

Questions I Get

What does the orange peel do? Will the soup taste like oranges?

This isn’t going to taste like oranges; instead, it will taste like something else altogether, but something more interesting. A 2-inch strip of peel in the simmer provides a warm, aromatic backbone that is difficult to pinpoint in the finished bowl. People usually ask what the soup is, and almost never guess orange. This is a classic Provençal/Spanish move that almost no one does with lentil soup, and that’s exactly why it is worth doing.

Do I have to make the pickled onions, or can I skip them?

You can leave them out; the soup will still be good. The effort is minimal and so the bar for skipping should be set high as they are an upgrade and take about 90 seconds of active effort. They offer soup with extra color, crunch, and a much needed second hit of acidity. They also last 1-2 weeks and make everything else in your fridge taste better, so they are basically never wasted.

Can I make the pickled onions further ahead?

There is no question; they get better after a few hours and after one or two days, they become excellent. Make a jar at the start of the week and use them on this soup, plus sandwiches, tacos, fried eggs, avocado toast, grain bowls, and anything else that wants brightness.

What kind of lentils should I use?

Green or brown lentils are default options here as they will maintain their shape throughout the cooking process, providing texture, and visual recognition, to the lentil soup. If you can source them, a minor step up are the French Le Puy lentils.

Red lentils are an option as well but they cook in 15 minutes, breaking down completely, and will result in a thicker, porridge like consistency to the soup. Yellow split peas should also be avoided as they are not the same thing and act differently.

Do I need to soak the lentils?

Unlike dried beans, lentils don’t need soaking and cook much faster. Just rinse them in a strainer and look for any little stone or other debris (yes, packaged lentils still have them more than you’d think).

Can I make this in an Instant Pot?

Certainly, I will use the Sauté function on the Instant Pot, and for about ten minutes, I will Sauté the mirepoix and bloom the spices. Next, I will add lentils, tomatoes, broth, a bay leaf, and an orange peel to the pot. Following that, I will set the pot to high pressure for 12 minutes, and will wait for a natural release of pressure. Once the pot is depressurized, I will stir in spinach and vinegar. I will also prepare the pickled onions first.

Can I make this fully vegan?

Of course, please use vegetable broth and omit the Parmesan rind. As described, the soup is 100% plant-based. We have a dollop of coconut yogurt on the table that can be used for a dairy substitute.

What’s the deal with the vinegar at the end? Can I skip it?

Stop right there, please! Soup has that muddy taste until acid is introduced after a long simmer. It’s the acid that gives it a clean and finished flavor. You can substitute the lemon juice for vinegar. The soup will feed you even if you don’t have a protein, but it will feel like something is missing – because it is.

Wrapping Up

Lentils have been recommended for consumption for decades now, but not for the enjoyment of eating them. It could be said that they have been relegated into the “good for you” category and put next to oat bran and quinoa in the cultural pantry, and at potlucks served by people whose other dishes you wouldn’t go back for either.

This soup is my small case that the lentil was always more interesting than its reputation, and that the smoked paprika, an orange peel strip, a tablespoon of vinegar, and a spoonful of pickled onions on top were the only things that stood between it and food you’d cook on purpose. One bag of lentils, one can of tomatoes, half a red onion, and a Tuesday become a meal.