Lentil soup is one of the most easiest and tastiest soup recipes around. It’s also very easy to tweak the recipe to suit your preferences or your ingredients on hand. If you want a delicious meal that you can pull straight out of the pantry, this tomato lentil soup recipe is for you. Bonus, it’s also really economical and a great way to feed a crowd.

lentil soup in a bowl with a spoon

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Recipe for Tomato Lentil Soup


  • 2 cups (1 pound) of raw lentils – green, red or brown are all great in this soup
  • 1 small yellow onion, diced
  • 2-3 medium carrots, chopped
  • 1 cup of celery, chopped
  • 10 cups of water*
  • 3 bay leaves
  • 3 tablespoons of tomato paste
  • 1 tablespoon of all-purpose flour

A large stock pot or dutch oven.

As always, I prefer to use my trusty cast iron dutch oven. It’s the most useful cooking vessel I own. If you want to invest in one for yourself (your only regret will be not doing it sooner!), I recommend this dutch oven.

*My recipe starts with water and makes a very quick vegetable stock to cook the lentils in. If you have stock, you can substitute that for some or all of the water and simply add the lentils, onions, carrots and celery all at once.


FIRST – To make a really flavorful soup, start by flavoring the cooking water. In the dutch oven, heat a couple teaspoons of olive or vegetable oil. Add the onion, carrots and celery and saute for several minutes, until the onions are transparent and aromatic.

SECOND – Add the water and salt to the dutch oven, and bring to a boil. Let the water gently boil for 15-20 minutes. This will make a quick, light vegetable stock. Sauteing the aromatics and then briefly boiling them will add more flavor to the lentils than simply throwing everything into the water together.

celery, onions and carrots in dutch oven

THIRD – While the water is boiling, rinse the lentils in a colander and pick out any malformed, dried up or otherwise imperfect lentils. Once the aromatics have boiled for 15-20 minutes, add the lentils and bring to a roiling boil. As soon as the pot reaches the roiling boil, turn off the heat down to low and let the soup simmer for at least 45 minutes. It’s fine, good even, to go longer than 45 minutes but keep an eye on the pot. Lentils cook very fast and they can easily boil dry and burn. Make sure they are never above a simmer and stir them often.

FOURTH – Combine the tomato paste and flour in a small bowl. Add a tablespoon or so of the cooking liquid from the pot, stir to combine and form a slurry. Once the flour, tomato paste and cooking liquid are thoroughly combined and there are no lumps, add the slurry to the soup. Raise the heat to medium and stir until the slurry is mixed into the soup. Cook on medium for 5 minutes. As the slurry cooks, it will thicken the soup slightly and add a wonderful tomato flavor.

FIFTH – Taste the soup. The lentils should be tender but not mushy. Add more salt and pepper to taste, and any other seasonings you wish. If the soup is not as thick as you’d like, let it simmer a few more minutes until the desired consistency is reached.


This is a very forgiving recipe, but it is easy to burn the lentils or over cook them if you’re not used to cooking lentils. When in doubt, lower the heat and cook longer rather than using a higher flame. Keep a close watch and stir often.

As noted in the intro, you can use vegetable or chicken stock as the cooking liquid. In that case, it’s still nice to saute the aromatics in the dutch oven before adding the stock, but you can skip simmering them. If you like really crisp aromatics in your soup, or if you generally have stock on hand, you may prefer this method.

For a stronger tomato flavor, you can increase the amount of tomato paste by one or two tablespoons.

It’s really easy to play around with this recipe, once you master the basic version. Here’s a few delicious ideas:

  • add a cup of finely chopped red or green sweet peppers. They work best when you add them at the same time as the lentils.
  • spice it up with jalapeno, chili or other hot peppers – if you like spice, throw in one, or even two, seeded, chopped peppers when you add the lentils
  • make a heartier soup by adding two cups of chopped sweet potato – I like to add it at the beginning, when I saute the aromatics but you can also add it with the lentils
  • give the soup a smoky flavor by including a teaspoon of paprika to the slurry. Then top with a handful of chopped parsley or cilantro.
  • top the soup with chunks of avocado, cilantro and a dollop of sour cream

Those are just a few ideas. The basic flavor profile of the soup is earthy and aromatic. It’s wonderful on its own but it’s also a great backdrop for other flavors. I like to serve it with a crisp salad and a loaf of beer bread.

This soup keeps for several days in the fridge and is really easy to freeze for a quick dinner later.

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What kind of lentils should I use for this lentil soup?

Great question! There are three main types of lentils – green, brown and red. All three will work for this soup, but you’ll need to tweak the cooking time depending on which type you use.

green, brown and red lentils in dishes

If you use brown lentils, they cook in 30-40 minutes and hold their texture well. They’re easy to find and they’re probably the most foolproof choice for this soup recipe. Their flavor is also fairly mild, so if you plan to tweak the flavors, brown lentils are a good choice.

Green lentils are very sturdy when cooked, so if you like a firmer texture to your lentils, go with green. They need 40-45 minutes to cook. Their flavor is a bit more bold and peppery, so they can be a great choice if you want the lentils to be the primary flavor.

To use red lentils, reduce cooking time to 20 minutes and use very low heat. Red lentils are the softest lentils. If you use red lentils, your soup will be softer and thicker, with a flavor that is a little sweeter and nuttier. Their sweetness makes them a great choice if you want to spice your soup up.

Buying Lentils

One of the best things about lentils is that they’re a very low cost food and they store well, making them a delicious, filling and nutritious pantry staple. While they are easy to find at nearly any grocery store, I actually order mine in 25 pound bags from Azure Standard, a fantastic grocery company. My family and my chickens all eat lentils*, so buying them in bulk saves us a lot of money. And, honestly, it’s kind of cool and really convenient to have all of our grains stocked up.

*It’s safe to feed lentils to chickens but legumes like beans should be cooked before your flock eats them!