My easy slow cooker lentil soup is the ultimate set-it-and-forget-it meal. This soup is hearty, healthy, and packed with flavor! It's vegan and gluten-free, too, so everyone can enjoy a bowl!
Soup season is all year long, as far as I'm concerned. There's not a single day of the year that I couldn't go for a big bowl of soup! But there are days when I'm not up for doing much cooking. That's where slow cooker soups and stews come in. I'm talking about dishes like my vegan lasagna soup, vegan slow cooker chili, vegan slow cooker stew, and vegan slow cooker curry.
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Lentil soup is one of my absolute favorite soups, and I can't imagine going without it because the weather doesn't inspire me to cook. So I decided it was time for some slow cooker lentil soup. This soup is every bit as delicious as my classic lentil soup, although you'll find the spices are a bit different — more in line with my Mediterranean red lentil soup. It's every bit as delicious as both of those dishes, but cooks up super easy and practically hands-free in the slow cooker!
Ingredients You'll Need
Below you'll find a list of ingredients in this recipe, with notes and substitutions. Scroll all the way to the bottom of the post to see the full recipe, including the amount of each ingredient.
- Lentils. We're using dried brown lentils, which are generally the most common variety. You should be able to substitute other types, like red or green lentils, but you might need to adjust the cook time. Red lentils generally cook quicker, while green cook a bit slower.
- Carrots.
- Celery.
- Onion.
- Garlic.
- Spices. You'll need some ground cumin and coriander. You can get both in the spice aisle of most grocery stores.
- Vegetable broth.
- Diced tomatoes. You can get diced tomatoes packed in either juice or sauce — either will work for this recipe!
- Salt and pepper.
How It's Made
Below is a detailed photo tutorial on how to make this dish. Scroll all the way down if you'd like to skip right to the recipe!
Step 1: Combine the lentils, diced onion, sliced carrots, diced celery, minced garlic, spices, and vegetable broth in a slow cooker. Cover it and cook everything until the lentils and vegies are tender.
Tip: The recipe gives you cook times in ranges. The exact amount of time needed for your soup will depend on your slow cooker (they vary a bit!), and how tender you like your lentils and veggies. Cook the soup for less time if you like things a bit firm, more time if you like your lentils and vegetables soft.
Step 2: Stir in the tomatoes and let the soup cook a bit longer, just to heat them up.
Tip: The acid in tomatoes can prevent lentils from softening when they cook. This is why we're adding them towards the end of the recipe.
Step 3: Your slow cooker lentil soup is ready to enjoy! Give it a taste-test and season it with some salt and pepper before ladling it into bowls and digging in.
Frequently Asked Questions
Yep! There are no gluten containing ingredients in this recipe.
Leftovers will keep for about three days in an airtight container in the fridge, or for up to three months in the freezer. They can be reheated in a saucepan on the stove, or in the microwave. Add a splash of water if the soup has gotten too thick during storage.
Nope! Just rinse them and remove any debris, then add them to the slow cooker.
Variations
- Savory spices. Skip the cumin and coriander, and instead season your soup with two teaspoons of dried thyme, one teaspoon of dried rosemary, and a bay leaf, just like I did with my classic lentil soup.
- Curried variation. Add two teaspoons of curry powder, and one teaspoon of garam masala to the soup. It'll taste similar to my curried lentil soup.
- Add veggies. Throw in some additional veggies, like a potato, shredded cabbage, finely chopped broccoli or cauliflower, kale, or green beans.
Like this recipe? If so, please stop back and leave me a review and rating below if you try it! Also be sure to follow me on Facebook, Pinterest or Instagram, or subscribe to my newsletter for more recipes like this one!
📖 Recipe
Slow Cooker Lentil Soup
Equipment
- Slow cooker (3 quart capacity or larger)
Ingredients
- 1 pound dried brown lentils
- 1 medium onion, diced
- 2 medium carrots, sliced
- 2 medium celery stalks, diced
- 3 garlic cloves, minced
- 1 teaspoon ground cumin
- ½ teaspoon ground coriander
- 8 cups vegetable broth
- 1 (14.5 ounce/411 gram) can diced tomatoes
- Salt and pepper, to taste
Instructions
- Place the lentils, onion, carrots, celery, garlic, cumin coriander, and vegetable broth into a (3 quart or larger) slow cooker. Stir everything up, cover, and turn on the slow cooker. Cook the soup on high for 2 ½ to 3 ½ hours, or on low for 5 to 6 hours, until the lentils are soft and the vegetables are tender.
- Stir in the tomatoes and let the soup cook for about 20 minutes longer, just to heat up the tomatoes.
- Season the soup with salt and pepper to taste. Serve.
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Delicious! I had fun with this recipe! Thank you for sharing!
Do I add all the liquid from the diced tomatoes tin, or drain it? Thank you.
Add the liquid with the tomatoes. Enjoy!
Very tasty soup, I added potato and spinach and it worked well. Loving the slow cooker recipes! Thanks :)
Just eat the soup, Steve. If you’re so concerned eat some bread.
If I am correct, the only protein in recipe is lentils. Lentils are not a "complete" protein in terms of all the essential amino acids for muscle development. A corresponding protein needs to be added to benefit the muscles.
So eat some bread with it.
And fish pee in the water,, get a life Steve.
Thank you for this recipe Alissa, perfect for a chilly & rainy day in late May. The lentils took 4 hours on High to soften but the soup is delicious! I added a few small cut up new potatoes too. Thanks again!