Super easy, healthy, and incredibly delicious, this cozy red lentil soup is seasoned with Mediterranean spices and a touch of harissa for some kick! This naturally vegan and gluten-free soup is perfect for chilly evenings.
This soup was one of my favorite things to cook when I was in law school. It’s go so much going for it! For one thing, it’s a pretty cheap meal (and funds were low back then). For another, the quick throw-stuff-in-a-pot-and-let-it-simmer approach to cooking was perfect during exams time.
I wasn’t the only one that was a big fan of this soup back then. At some point a mouse moved into the kitchen of the house I was renting, residing somewhere beneath my oven. Whenever this soup was cooking, he’d pop his little head out of one of the burners that weren’t then being used and turn his nose up in the air, sniffing away.
I didn’t really mind. It was cute and I took it as a compliment. I did get a little nervous at times that I’d light a burner without realizing he was approaching, so I got in the habit of banging on the stove top to scare him away before lighting up, just in case.
We eventually did have to relocate the mouse and his family. I just wasn’t comfortable with the thought of them scampering all over my dishes and utensils while I wasn’t looking. I’m happy to say that we caught them all with humane traps and relocated them to Philadelphia’s Fairmount Park, where they (as far as I’m concerned) lived out the rest of their little mouse lives happily.
Why Red Lentils?
I love the flavor and texture of split red lentils, but they’ve also got the advantage of quicker cooking time compared to other types of lentils. About 20 minutes of simmer time is all it takes for these lentils to completely soften up and fall apart.
Make sure your red lentils are split. Usually the ones available at supermarkets are, but occasionally I come across some that aren’t. If your lentils aren’t split, they’ll take much longer to cook, and your soup will have a completely different consistency.
What You’ll Need
- Olive oil. Any high heat oil will technically work, but olive will give your soup the best flavor.
- Spices. We’re using ground cumin and coriander.
- Red lentils. Make sure to use split lentils — not whole ones.
- Vegetable broth. I like Better Than Bouillon in seasoned vegetable flavor.
- Diced tomatoes. Use canned diced tomatoes that are packed in juice or sauce.
- Lemon juice. Use freshly squeezed juice for the best flavor.
- Harissa paste. This is a spicy north African chili paste. Many supermarkets carry it in the international foods section (Trader Joe’s has it!). You can substitute another hot sauce or just leave it out for a milder soup.
- Herbs. Top your soup with some fresh parsley or cilantro.
How to Make Red Lentil Soup
Follow along with the photos below if you need some guidance on how to make this dish, or scroll all the way to the bottom of the post if you just want the recipe!
- Heat up some olive oil in a large pot, then add diced onion. Sweat the onion for a few minutes, until it begins to soften up.
- Add minced garlic and your spices and sauté them very briefly with the onion. Sautéing the spices for a minute (but no longer!) brings out their flavors.
- Add broth, tomatoes and your red lentils. Raise the heat and bring the liquid to a simmer.
- Let everything simmer for a bit, until the lentils are soft. Add a squeeze of lemon juice. If you like your soup on the spicy side, stir in some harissa paste at the end.
Leftovers & Storage
Leftovers of this soup keep very well for about 3 days in the fridge. The soup may thicken up a bit over time, but I personally like that! If you don’t, just thin it with a bit of broth or water.
Frequently Asked Questions
It sure is!
Perhaps, as long as the lentils you use are split. If they’re not split, the tomatoes could prevent them from cooking fully.
The harissa gives it a little kick. Use extra if you’d like your soup to be extra spicy, or leave it out for a heat-free version.
More Lentil Recipes
Check out my video to see just how easy this soup is to make!
Mediterranean Red Lentil Soup
- 1 tablespoon olive oil
- 1 medium onion, diced
- 4 garlic cloves, minced
- 1 tablespoon ground cumin
- 1 teaspoon ground coriander
- 1 ½ cups dried red lentils
- 5 cups vegetable broth (4 cups if using the Instant Pot method)
- 1 (14 ounce) can diced tomatoes
- 2 tablespoons lemon juice, or to taste
- Harissa paste, to taste (optional)
- Fresh chopped cilantro or parsley, for serving
- Heat the olive oil in a large saucepan over medium heat. Add the onion and cook, stirring occasionally, until soft and translucent, about 5 minutes.
- Add the garlic, cumin and coriander, and sauté for another minute, until the garlic becomes very fragrant.
- Stir in the lentils, broth and tomatoes.
- Bring the liquid to a boil, lower the heat to a simmer, and allow to continue simmering, uncovered, until lentils are soft, about 20 minutes. Thin the soup with some water if it becomes too thick while simmering.
- Stir in the lemon juice and harissa (if using). Season the soup with salt and pepper to taste.
- Ladle into bowls and top with parsley and/or cilantro.
Instant Pot Method
- Press the “sauté” button on your Instant Pot and add the oil.
- Give the oil a minute to heat up, then add the onion. Cook the onion for about 3 minutes, stirring occasionally, until soft and translucent.
- Add the garlic, cumin and coriander, and sauté for another minute, until the garlic becomes very fragrant. Press the “cancel” button.
- Stir in the lentils, 4 cups of broth, and tomatoes.
- Place the lid on your Instant Pot and set the valve to the “sealing” position. Press the “pressure cook” or “manual” button and set the pressure to high. Set the soup to cook for 10 minutes.
- When the soup has finished cooking, carefully move the valve to the “venting” position. Let the pressure release completely.
- Remove the lid from the Instant Pot. Stir in the lemon juice and harissa (if using). Season the soup with salt and pepper to taste.
- Ladle into bowls and top with parsley and/or cilantro.