Easy Slow Cooker Lentil Soup

white bowl of crockpot lentil soup with fresh herbs and crusty bread on the side

This easy slow cooker lentil soup is made with simple pantry ingredients like green lentils, celery, carrot and spinach making for a hearty vegan and vegetarian meal. Plus instant pot and stovetop directions!

Course Soup

Diet Gluten Free, Vegan, Vegetarian

Keyword Crockpot, lentil, Slow Cooker, soup

Prep Time 5

Cook Time 4

Total Time 4 5

Servings

Calories 241

Author Robyn Conley Downs

Equipment

Ingredients

1 medium yellow onion chopped
1 cup chopped celery
2 cups chopped carrot
2 cloves garlic minced or finely grated
2 teaspoons kosher salt divided
1 ½ cups dry green lentils (or brown lentils) rinsed and picked over
1 (15-oz) can petite-diced tomatoes
6-8 cups vegetable stock or chicken stock
1 large bay leaf or 2 small bay leaves

To Add at the End

4 cups baby spinach
1 teaspoon red wine vinegar

Optional Serving Suggestions

Instructions

Slow Cooker Directions

Add the onion, celery, carrot, garlic, 1 teaspoon salt, lentils, tomatoes, stock and bay leaf to a 6-quart slow cooker, stirring to combine. Do not add the spinach, it will be added at the end.
Cover and cook on high for 4-6 hours or on low for 6-8 hours, or until the veggies and lentils are soft.
Remove the lid, remove the bay leaf, add the vinegar, and stir to combine. Add an additional 1-2 cups of stock to thin the soup if necessary. Taste and add the remaining 1 teaspoon salt, plus additional vinegar if desired.
Using an immersion blender, blend for 5-10 seconds. Alternatively, carefully, remove ½ to 1 cup of cooked soup to a blender. Cover, blend on high, then add back to the soup, stirring to combine. Note: Blending for just a few seconds will add a creaminess to the soup, while leaving the texture of most of the lentils and vegetables intact.
Add the spinach, and stir to combine. Serve with a generous drizzle of olive oil, and any other toppings you like.

Instant Pot Directions

Set a 6-quart pressure cooker to saute mode for 8 minutes. Add 1 tablespoon olive oil, onion, a pinch of salt, and cook, stirring occasionally, until the onions are soft.
Cancel the saute function. Add the celery, carrot, garlic, 1 teaspoon salt, lentils, tomatoes, stock, and bay leaf, stirring to combine.
Secure the lid, select the manual setting, and set it to high pressure for 15 minutes.
When the pressure cooker timer is done, allow to naturally release for 15 minutes.
Follow remaining slow cooker steps 3-5.

Stovetop Directions

Heat 1 tablespoon olive oil over medium high heat in a large Dutch oven. Add the onion and a pinch of salt, stirring to combine. Cook until the onions soften, about 8 minutes, stirring occasionally.
Add the celery, carrot, garlic, and 1 teaspoon salt, stirring to combine. Cook for an additional 2 minutes, stirring occasionally.
Add the lentils, tomatoes, bay leaf, and stock, stirring to combine. Cover, bring to a boil, then reduce to a simmer.
Cook, covered, until the lentils are soft, about 35-45 minutes, stirring occasionally.
Follow remaining slow cooker steps 3-5.

Notes

If the final soup tastes flat or bland to you, add more salt, 1 teaspoon at a time, until the flavor seems more robust. You can also add an additional tablespoon of red wine vinegar to taste.
See blog post above for ingredient notes and substitutions.
Dried brown, green or French lentils work interchangeably here. Do not use red lentils.
The heat of slow cookers can vary, as can the amount of liquid lentils absorb during the cooking process. If necessary add additional stock at the end, to achieve your desired consistency.
This soup will also thicken considerably as it cools, so if you prefer it thicker, allow to cool for 30 minutes prior to serving.
Sodium will very based on type of stock and tomatoes used. For a lower sodium option use low sodium stock and tomatoes.
Optional serving suggestions: extra virgin olive oil, freshly cracked pepper, freshly grated parmesan cheese (traditional or vegan), fresh parsley, red pepper flakes, crusty bread

Nutrition