Easy Lentil Soup

Lemon zest, garlic, and parsley are the secret to simple, but ultra-flavorful, lentil soup.

By
J. Kenji López-Alt
Kenji Lopez Alt
Culinary Consultant
Kenji is the former culinary director for Serious Eats and a current culinary consultant for the site. He is also a New York Times food columnist and the author of The Food Lab: Better Home Cooking Through Science.
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Updated April 05, 2023
A big bowl of lentil soup, topped with gremolata, next to a small bowl of gremolata with olive oil for topping.

Serious Eats / J. Kenji López-Alt

Why It Works

  • Keep it simple with basic aromatics and good stock as the background for dried lentils.
  • A mixture of parsley, garlic, and lemon zest combined with olive oil goes into the vegetables as they are sautéed and also gets stirred into the soup just before serving for maximum flavor.

My wife loves lentil soup, which means I make a lot of it. It's my go-to meal when I want to make something I know she'll enjoy without having to spend too much time, thought, or effort on it. The thing is, my wife likes it ultra simple. I mean, about as simple as you can get. Nothing more than a basic mirepoix, some good stock, and dried lentils for her, please.

I, on the other hand, prefer to punch mine up with other flavors, like, say, curry or coconut and habanero. Every time I do, my wife complains.

All the ingredients for lentil soup with gremolata: lentils, leek, parsley, carrot, onion, celery, garlic, and stock.

Serious Eats / J. Kenji López-Alt

Little does she know that she's been the subject of a little experiment of mine. See, every time I make lentil soup, I push the boundary of what an acceptable level of extra flavor is for her, bouncing back and forth between too much (hello, coconut) and just enough. I've finally hit on what I believe is the upper limit of her tolerance, and therefore the most flavor-packed lentil soup I can make while still keeping my home life content.

How to Add Flavor to Lentil Soup

Zesting a lemon on a microplane for gremolata.

Serious Eats / J. Kenji López-Alt

The secret to this version? Gremolata, the Italian condiment of chopped fresh parsley, lemon zest, and garlic typically served with osso bucco. In this case, I use it to develop two distinct levels of flavor, once while sautéing my aromatics, and again by stirring it in at the very end.

Minced garlic, lemon zest, and fresh parsley for gremolata.

Serious Eats / J. Kenji López-Alt

While a typical gremolata is a dry condiment, I combine mine with some extra-virgin olive oil. As the gremolata sits while the soup simmers, the fat-soluble aromatic compounds in the lemon, parsley, and garlic are drawn out into the oil, making it much easier to add mellow flavor to the whole bowl of soup when we serve it.

Making Lentil Soup, Step-By-Step

To start out, I cook my basic mirepoix—diced onions, carrots, celery, and leek in this case—in some extra-virgin olive oil (don't worry—the steam coming off the vegetables will keep the oil down to a low enough temperature that you won't scorch it and ruin those extra-virgin flavors) just until softened.

Stirring diced onion, carrot, celery, and leek together for lentil soup.

Serious Eats / J. Kenji López-Alt

Then I add half of my gremolata mixture, stirring it in and sautéing until aromatic.

Stirring gremolata into lentil soup aromatics.

Serious Eats / J. Kenji López-Alt

Are you ready for the hard part? Yes? That's really unfortunate, as the hard part is already over.

All we have left to do is add our lentils (brown or Puy lentils will both work fine) along with some good vegetable or chicken stock and a couple of bay leaves, bring it to a simmer, and walk away for an hour.

Stirring almost finished lentil soup on the stovetop.

Serious Eats / J. Kenji López-Alt

When we get back, the lentils should be falling apart-tender and packed with flavor.

I like my lentil soup to be lightly blended but not smooth. Brown and sludgy is how I'd describe it if I were simultaneously really good at describing things and really terrible at writing menus.

You get what I mean though, right?

Squeezing lemon juice into finished lentil soup.

Serious Eats / J. Kenji López-Alt

A shot of lemon juice at the very end brightens it up with some acid before the final kicker: an extra drizzle of oily gremolata drizzled on top of each serving.

If you're feeling particularly feisty, you should consider doing what I did with one of these batches: adding a good pinch of dried chile flakes (I used dried Thai chile) to the gremolata for just a kiss of heat.

Taking a spoonful of lentil soup, garnished with gremolata.

Serious Eats / J. Kenji López-Alt

Now here's a soup that we can both be happy with, and while lentil soup may not be the most exciting thing in the world, a tranquil marriage is.

October 2014

Recipe Details

Easy Lentil Soup Recipe

Active 25 mins
Total 90 mins
Serves 3 to 4 servings

Ingredients

  • 2 tablespoons grated zest and 2 tablespoons juice from 1 to 2 lemons

  • 1/2 cup chopped fresh parsley leaves

  • 6 medium cloves garlic, minced (about 2 tablespoons)

  • 1/2 cup extra-virgin olive oil, divided

  • Kosher salt and freshly ground black pepper

  • 1 large leek, white and pale green parts only, finely chopped (about 1 cup)

  • 1 medium onion, finely diced (about 1 cup)

  • 1 large carrot, peeled and finely diced (about 1 cup)

  • 2 stalks celery, finely diced (about 1 cup)

  • 1 pound dried brown or Puy lentils

  • 2 bay leaves

  • 2 quarts homemade or store-bought low-sodium chicken stock or vegetable stock

Directions

  1. Combine lemon zest, parsley, garlic, and half of olive oil in a medium bowl and stir with a fork until homogenous. Season to taste with salt and pepper and set aside.

    Stirring together gremolata ingredients with olive oil: parsley, garlic, and lemon zest.

    Serious Eats / J. Kenji López-Alt

  2. Heat remaining olive oil in a large Dutch oven over medium-high heat until shimmering. Add leek, onion, carrot, and celery and cook, stirring frequently, until softened but not browned, about 5 minutes. Add half of parsley-lemon mixture and cook, stirring, until fragrant, about 1 minute. Add lentils and stir until coated in oil. Add bay leaves and stock. Bring to a boil, reduce to a bare simmer, cover with lid slightly cracked, and cook until lentils are completely tender and falling apart, about 1 hour, adding water as necessary (lentils should be fully covered at all times).

    Adding stock to lentil soup.

    Serious Eats / J. Kenji López-Alt

  3. Using a hand blender, blend soup until as smooth as desired. Alternatively, transfer half of soup to a standing blender, blend until smooth, and fold back into remaining soup. Whisk in lemon juice and season to taste with salt and pepper. Serve, drizzling extra lemon-parsley mixture on top of each serving. Soup can be stored in the refrigerator for up to 5 days.

    Using an immersion blender to partially blend lentil soup.

    Serious Eats / J. Kenji López-Alt

Special Equipment

Microplane grater, large Dutch oven, immersion blender or standing blender

Nutrition Facts (per serving)
339Calories
27gFat
17gCarbs
9gProtein
×
Nutrition Facts
Servings: 3 to 4
Amount per serving
Calories339
% Daily Value*
Total Fat 27g35%
Saturated Fat 4g19%
Cholesterol 0mg0%
Sodium 1638mg71%
Total Carbohydrate 17g6%
Dietary Fiber 3g12%
Total Sugars 6g
Protein 9g
Vitamin C 22mg110%
Calcium 103mg8%
Iron 3mg16%
Potassium 775mg16%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

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