Spicy Lentil Soup

Spicy lentil soup is an easy lentil soup recipe made from pantry staples: brown lentils, fire-roasted tomatoes, carrots, celery, and onion, warmed up with cumin and red pepper flakes. It all simmers in one pot on the stove, with slow cooker and Instant Pot directions too. If you like my red lentil stew, this is the brothier one with more heat.

Hearty, Nutrient-Dense, Easy Spicy Lentil Soup Recipe

I’ve said it many times before, and I’ll keep saying it: lentils are one of the best things to keep in a budget-friendly plant-based kitchen. They’re a good source of fiber, plant-based protein, iron, and folate. Plus, they’re super versatile, whether you’re making vegan sloppy joes, meatballs, burgers, or a classic hearty, easy lentil soup.

This spicy lentil soup is made with just a dozen simple, inexpensive kitchen and pantry staples in one pot. The combination of mirepoix (celery, carrot, and onion) with lentils, tomatoes, and garlic makes for an earthy, savory, slightly sweet flavor, made all the more addictive with earthy cumin, aromatic Italian seasoning, and red pepper flakes for a touch (or more) of heat. Have extra brown lentils? My bean and lentil chili uses them with kidney beans, corn, and red lentils.

Whether you simmer it on the stove, in an Instant Pot, or in a crockpot, you end up with a comforting, filling, flavor-packed meat-free meal that’s naturally dairy-free (and gluten-free, as long as your bouillon is). Plus, it tastes even better on day two, and it freezes well!

Looking for more hearty vegan soup ideas? Check out our split pea soup, carrot lentil soup, Mexican bean soup, lemon lentil soup, lentil potato soup, or vegetable barley soup.

The Ingredients

• Lentils: We used dried brown lentils, but green lentils will also work.
• Mirepoix: Make a flavor-packed spiced lentil soup with plenty of depth with the addition of onion (yellow or white), carrot, and celery. To save time, you could use pre-prepared mirepoix mix (sometimes labeled ‘soup base’).
• Garlic: Fresh garlic cloves are best, but powdered garlic works in a pinch.
• Tomatoes: Use high-quality canned, diced, fire-roasted tomatoes.
• Vegetable broth: Use pre-made broth or a combination of bouillon cubes/ powder + boiling water. Use a reduced sodium version, if preferred.
• Oil: Use a neutral-flavored cooking oil, like olive oil or avocado oil.
• Seasonings: We use a simple yet flavor-packed combination of ground cumin, Italian seasoning (or dried thyme/rosemary), red pepper flakes (adjust the amount to taste, or use cayenne pepper), sea salt (or soy sauce for umami), and black pepper.
• Spinach: (optional) Fresh or frozen, for extra nutrients. Kale would work, too.
• Parsley: (or cilantro) To garnish, for a touch of freshness and aromatic depth.
• Lemon: A small amount of lemon juice wakes up the flavor and adds depth. Lime juice, apple cider vinegar, or even balsamic vinegar should also work.

What Could I Add to Spicy Tomato Lentil Soup?

There are several ways to adapt this recipe for spicy lentil soup, including:

• Smoked paprika: For a smoky flavor in the spicy tomato and lentil soup.
• Carrot and lentil soup: Increase the ratio of carrots (sliced or shredded) to lentils.
• More vegetables: Bulk up the lentil and spinach soup further with peas, sweet potato (in ½-inch chunks), squash, pumpkin, mushrooms, cauliflower, zucchini, etc. Love it with pumpkin? Try my red lentil pumpkin soup.
• Creamy soup: Add some full-fat canned coconut milk or dairy-free cream.
• Vegan yogurt: Add a dollop of dairy-free yogurt to the spicy lentil soup when serving for creaminess.
• Vegan sausage: Add some vegan sausage to boost the protein further in this vegan spicy tomato lentil soup.

How to Make Spicy Lentil Soup

• First, sort through (to remove debris) and rinse the lentils. Then, finely dice the onion, carrot, and celery. Also, mince the garlic.
• Meanwhile, heat the oil in a large, heavy-based Dutch oven/pan over medium-high heat.
• Once hot, add the onion, garlic, carrot, celery, and red pepper flakes. Reduce the heat to medium-low, cover with a lid, and sauté for 5 minutes, stirring often.

• Add the cumin and Italian seasoning and saute for a further 20-30 seconds.

• Next, stir in the tomatoes, lentils, vegetable broth, salt, and pepper and return the heat to medium-high.

• Cover with a lid and bring to a boil, then immediately reduce the heat to a simmer and cook for about 40 minutes, lid on (stirring occasionally).
• Taste the spicy lentil soup and adjust any of the seasoning then add the spinach and parsley (if using) and lemon juice. Cover it with a lid to allow the spinach to naturally wilt for just a few minutes, then serve and enjoy!

Slow Cooker Spicy Lentil Soup

Complete steps 1 to 3 as written above, then in step 4, transfer everything (except the spinach, parsley, and lemon) to a crockpot.

Cover and cook over LOW for 7-9 hours (add more broth at any point if needed) or on HIGH for 3-4 hours. Stir in the final ingredients, leave for several minutes for the spinach to wilt, and enjoy!

Instant Pot Lentil Soup

Use the sauté function for the first 3 steps, then add the remaining ingredients (except spinach, parsley, and lemon). Stir well, then cover and cook on manual HIGH pressure for 15 minutes.

Once the timer goes off, allow the pressure to release naturally before opening the lid. Stir in the last ingredients and replace the lid for just a few minutes, then serve the spicy tomato lentil soup, and enjoy.

Spicy Lentil Soup FAQs

Pro Recipe Tips

• To adjust the consistency: If you’d prefer a brothier soup, add more vegetable broth. For a smoother consistency, blend some or all of it.
• If blending: Hold the lid down while it blends, and pause now and then to lift the lid and let the steam escape.
• Bloom the spices: Don’t skip these steps as it really helps to bring out their flavor and add depth to the soup flavor.
• Season to taste: Make sure to taste the soup after the simmering step and adjust any of the ingredients to your liking (spice, salt, etc.).
• Make plenty of leftovers: This spicy lentil and tomato soup will taste even better on day two, giving time for the flavors to meld.
• Don’t skip the lemon juice: A small squeeze of lemon really wakes up the flavor and adds depth.

Serving Suggestions

Enjoy this incredibly satisfying, nutrient-dense spicy tomato lentil soup alone or in smaller portions with:

• Buttered bread, flatbread, garlic bread, etc.
• A vegan grilled cheese or sandwich
• Sauteed/ Roasted vegetables (like broccoli, green beans, asparagus, etc.)
• A simple leafy green salad (like Caesar salad, a kale salad, etc.)

Storage Instructions

Allow the spicy lentil spinach soup to cool and then store the leftovers in an airtight container in the refrigerator for 4-5 days. Plus, it’ll taste even better on day two and three.

You can also freeze it in Ziplock/Stasher bags (spread flat), a silicone muffin tray, or freezer-safe containers for up to 3 months. Leave it to thaw in the refrigerator overnight before reheating.

Reheat the spinach lentil soup in a microwave (1-2 minutes on full power) or on the stovetop over medium-low heat until warm. Add extra broth or water, if needed.