Slow-Cooker Creamy Tomato Lentil Soup
Updated August 24, 2026
- Total Time
- 4 hours 10 minutes
- Prep Time
- 10 minutes
- Cook Time
- 4 hours
- Rating
- Comments
- Read comments
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Ingredients
1 pound 12 ounces tomatoes, roughly chopped, divided (see Tip)
1 ½ cups red lentils, rinsed
4 garlic cloves, smashed and chopped
1 large basil sprig plus 1 cup roughly chopped basil
¼ cup tomato paste
2 tablespoons olive oil
1 tablespoon kosher salt (such as Diamond Crystal)
1 ½ teaspoons sugar
1 teaspoon dried oregano
Black pepper
Juice of 1 lemon
¾ cup heavy cream
Preparation
- Step 1
In a 6- to 8-quart slow-cooker, combine 5 cups water, about 1 pound of the tomatoes (no need to be exact) along with any juices, the lentils, garlic, basil sprig, tomato paste, olive oil, salt, sugar, oregano and several generous grinds of black pepper. Cook on high for 4 hours.
- Step 2
Remove and discard the basil sprig. (It’s OK if it falls apart.) Whisk the soup vigorously to help the tomatoes and lentils fall apart and become smooth.
- Step 3
Stir in the remaining tomatoes and chopped basil, plus the lemon juice and the cream. Taste for seasoning and add more salt or pepper if necessary. The soup will thicken as it cools; add more water as necessary for the texture you like.
Feel free to use any kind of tomato that you have on hand: Almost-falling apart beefsteaks would be lovely, as would cherry tomatoes or plum tomatoes. (If you use all cherry tomatoes, just be aware that there will be more tomato skin in the soup, so choose thinner skinned varieties, like Sungold, if you can.) Outside of tomato season, use a 15-ounce can of tomatoes to start, and finish with chopped cherry or grape tomatoes, which tend to be better than other varieties out of season.
Private Notes
Comments
I made this with Thai basil and coconut milk instead of cream. Really good.
Baking SODA. The idea is to provide a little bit of alkaline to neutralize the acid when mixing with the dairy. You don’t need a lot. Baking powder is slightly acidic. It will not do the same job.
@Olga - absolutely not! It's ready in about an hour on the stove (keep a lid on it to keep the heat in and encourage the lentils to cook all the way through!). For those who have had trouble with tomatoes and dairy "breaking" and getting grainy, add a healthy spoonful of baking powder to the pot! It will foam like crazy but stir well until the foam subsides and then add the dairy. Thanks to cookbook author Helen Myhre of the Norske Nook for that tip - game-changer!!! This soup is a favorite!!!
I used my Instant Pot slow cooker function and did everything I was supposed to do but it ended up NOT coming out the way it should’ve so I ended up having to cook it on the stovetop, which was successful and didn’t end up being 4 hrs. Next time, I’ll use stovetop again or use an actual slow cooker. The InstaPot experience was so underwhelming….
This was great! I only had coconut milk on hand so subbed that for the cream, and once it mellowed out I couldn't have told the difference. Topped with some homemade garlicky croutons for texture, and it was DELISH. Perfect for getting rid of some of our end-of-summer tomatoes.
Coconut milk sub, added carrots, shallot, cumin, paprika, chili garlic paste. Didn't have oregano so subbed thyme. Mix of garden tomatoes and fire roasted canned. Easy, delish.

