Warm, hearty, and packed with wholesome goodness, this Slow Cooker Lentil Soup is a comforting bowl of nourishment. With tender lentils, vibrant vegetables, and a rich blend of spices, every spoonful delivers a satisfying mix of earthy flavors and velvety textures. Perfect for busy days, it simmers effortlessly in just 4 hours, filling your home with an irresistible aroma.
This soup is a nutritional powerhouse, offering 21g of fiber and 18g of protein per serving, making it as filling as it is delicious. The subtle sweetness of carrots and tomatoes balances the savory broth, while a hint of warmth from spices ties it all together. Whether it’s a chilly evening or a quick weeknight meal, this soup is your go-to for comfort and convenience.
What You’ll Need for Slow Cooker Lentil Soup
- 2 Tablespoons olive oil (or substitute with avocado oil)
- 2 shallots, diced (or use 1 small onion as an alternative)
- 4 stalks celery, sliced into half-moons
- 4 medium carrots, sliced into rounds
- 1 teaspoon salt (plus extra for seasoning at the end)
- ½ teaspoon ground black pepper
- 1 teaspoon garlic powder (or 2 cloves fresh garlic, minced)
- 2 bay leaves
- 1 Tablespoon herbs de provence (or a mix of dried thyme, rosemary, and oregano)
- 28 ounces crushed tomatoes (1 can)
- 4 cups vegetable stock (low-sodium preferred)
- 1⅔ cups French green lentils (rinsed and drained)
- 2-inch parmesan rind (optional, but adds depth of flavor)
- 2 handfuls spinach (or substitute with kale or Swiss chard)
How to Make Slow Cooker Lentil Soup
- Sauté the veggies: Heat olive oil in a large skillet over medium-high heat. Add shallots, celery, and carrots. Season with 1 teaspoon salt and sauté for 5-7 minutes, until softened. Turn off the heat.
- Load the slow cooker: Transfer the sautéed veggies to the slow cooker. Add black pepper, garlic powder, bay leaves, herbs de provence, crushed tomatoes, vegetable stock, lentils, and parmesan rind. Stir to combine.
- Cook: Close the slow cooker and cook on high for 4 hours. The lentils should be tender, and the soup will thicken slightly.
- Add finishing touches: Open the slow cooker and remove the parmesan rind. Stir in the spinach until it wilts and melts into the soup.
- Season to taste: Taste the soup and add more salt and pepper if needed. Serve warm and enjoy!
Perfect Pairings: Serving Suggestions
This hearty Slow Cooker Lentil Soup is a meal on its own, but it pairs beautifully with a slice of crusty bread or a warm baguette for dipping. For a lighter option, serve it alongside a fresh green salad with a tangy vinaigrette. If you’re feeling fancy, sprinkle a little grated Parmesan or a drizzle of olive oil on top for extra richness.
Store It Right: Storage and Reheating Tips
This soup keeps well in the fridge for up to 4 days in an airtight container. To reheat, simply warm it on the stovetop over medium heat, stirring occasionally. If the soup thickens, add a splash of vegetable stock or water to loosen it up. For longer storage, freeze it in portion-sized containers for up to 3 months—just thaw overnight in the fridge before reheating.
Mix It Up: Recipe Variations
Feel free to customize this soup to suit your taste! Swap the spinach for kale or Swiss chard, or add diced potatoes for extra heartiness. For a smoky twist, stir in a teaspoon of smoked paprika or add a few drops of liquid smoke. If you’re not vegetarian, cooked sausage or bacon bits can add a savory punch. Get creative—it’s hard to go wrong!
Time-Saving Hacks
Short on time? Skip the sauté step and toss all the ingredients directly into the slow cooker. The soup will still turn out delicious, though the veggies may have a slightly softer texture. Alternatively, prep your veggies the night before and store them in the fridge, so you can quickly assemble everything in the morning.
Why the Parmesan Rind?
That Parmesan rind isn’t just for show—it adds a deep, savory umami flavor to the soup as it simmers. If you don’t have a rind on hand, you can substitute with a tablespoon of grated Parmesan stirred in at the end. Just be sure to remove the rind before serving, as it won’t fully melt!
Slow Cooker Lentil Soup
Ingredients
- 2 Tablespoons olive oil
- 2 shallots, diced
- 4 stalks celery, sliced into half-moons
- 4 medium carrots, sliced into rounds
- 1 teaspoon salt
- ½ teaspoon ground black pepper
- 1 teaspoon garlic powder
- 2 bay leaves
- 1 Tablespoon herbs de provence
- 28 ounces crushed tomatoes, (1 can)
- 4 cups vegetable stock
- 1⅔ cups French green lentils
- 2 inch parmesan rind
- 2 handfuls spinach
- Additional salt and pepper to taste
Instructions
- Saute. Heat the olive oil over medium-high heat in a large skillet. Add the shallots, celery, and carrots. Season with salt and saute until the veggies have softened. Turn off the heat.
- Load the slow cooker. Transfer the sauteed veggies to the slow cooker along with the pepper, garlic powder, bay leaves, herbs de province, crushed tomatoes, vegetable stock, lentils, and parmesan rind.
- Cook. Close the slow cooker and cook on high for 4 hours.
- Finishing touches. At the end of the cooking time, remove the lid from the slow cooker. Remove the parmesan rind and stir in the spinach. Stir until the spinach has melted.
- Season. Taste the soup and season with additional salt and pepper to taste.