Name: Slow Cooker Lentil Soup with Sweet Potatoes
Prep time: 15 min
Cook time: 8 h
Total time: 8 h 25 min
Yield: 6
Cuisine: Moroccan
Ingredients: 1 ½ cups (300g) red or brown lentils, rinsed and drained; 2 medium sweet potatoes (about 1.5 lbs / 680g), peeled and cubed; 1 large onion, diced; 2 carrots, diced; 4 garlic cloves, minced; 1 tablespoon fresh ginger, grated; 2 teaspoons ground cumin; 1 teaspoon ground turmeric; 1 teaspoon ground coriander; ½ teaspoon ground cinnamon; ¼ teaspoon black pepper; 6 cups (1.4 liters) vegetable broth; 2 tablespoons olive oil (optional, for sautéing); 1 teaspoon salt (or to taste); Juice of 1 large lemon (or to taste); 2 cups chopped kale or spinach (optional); Fresh cilantro or parsley, chopped (for garnish)

Slow Cooker Lentil Soup with Sweet Potatoes is a hearty, nourishing soup where protein-rich lentils and naturally sweet orange-fleshed sweet potatoes simmer slowly with aromatic vegetables, warm spices, and savory broth.

The long, gentle cooking creates deep flavor, tender lentils, and silky sweet potatoes in a comforting, colorful bowl finished with fresh herbs and a bright squeeze of lemon.

Why You’ll Love This Recipe

This Slow Cooker Lentil Soup with Sweet Potatoes is the ultimate set-it-and-forget-it meal that delivers maximum flavor with almost zero effort. The sweet potatoes add natural sweetness and beautiful color that perfectly balances the earthy lentils, while warm spices like cumin and turmeric make every spoonful fragrant and satisfying.

It’s naturally vegan, gluten-free, budget-friendly, and packed with plant-based protein, fiber, and vitamins—making it ideal for healthy eating, busy weeknights, or weekly meal prep.

The slow cooker does all the work, filling your home with wonderful aromas as it cooks. The soup tastes even better the next day as the flavors continue to meld, and it’s incredibly versatile. Whether you need a cozy lunch, a filling dinner, or a nourishing bowl to fuel your day, this recipe brings comforting, wholesome goodness with very little hands-on time.

Yield: 6 servings

Slow Cooker Lentil Soup with Sweet Potatoes

Hearty slow cooker lentil soup with sweet potatoes and warm spices

Prep Time 15 minutes

Cook Time 8 hours

Additional Time 10 minutes

Total Time 8 hours 25 minutes

Ingredients

1 ½ cups (300g) red or brown lentils, rinsed and drained
2 medium sweet potatoes (about 1.5 lbs / 680g), peeled and cubed
1 large onion, diced
2 carrots, diced
4 garlic cloves, minced
1 tablespoon fresh ginger, grated
2 teaspoons ground cumin
1 teaspoon ground turmeric
1 teaspoon ground coriander
½ teaspoon ground cinnamon
¼ teaspoon black pepper
6 cups (1.4 liters) vegetable broth
2 tablespoons olive oil (optional, for sautéing)
1 teaspoon salt (or to taste)
Juice of 1 large lemon (or to taste)
2 cups chopped kale or spinach (optional)
Fresh cilantro or parsley, chopped (for garnish)

Instructions

Prepare with excitement — Gather all your ingredients. This slow cooker soup will fill your home with the most comforting aromas as it gently cooks.
Layer the foundation — Place the rinsed lentils and cubed sweet potatoes into the bottom of your slow cooker.
Add the vegetables — Scatter the diced onion and carrots over the lentils and sweet potatoes.
Sprinkle the magic spices — Add the minced garlic, grated ginger, cumin, turmeric, coriander, cinnamon, black pepper, and salt on top.
Pour in the broth — Gently pour the vegetable broth over everything. If using olive oil for extra richness, drizzle it in now.
Give it a gentle stir — Stir everything together lightly so the spices start to coat the ingredients.
Set and forget — Cover and cook on LOW for 6-8 hours or on HIGH for 3-4 hours, until the lentils and sweet potatoes are completely tender.
Add the greens — If using kale or spinach, stir it in during the last 20-30 minutes of cooking until just wilted and bright green.
Brighten the flavors — Turn off the slow cooker. Stir in the fresh lemon juice, taste, and adjust seasoning with more salt or pepper if needed. Let it rest for 5 minutes.
Serve with joy — Ladle the warm, fragrant soup into bowls. Drizzle with a little extra olive oil if desired, sprinkle with chopped fresh cilantro or parsley, and enjoy this nourishing, colorful bowl of slow-cooked comfort!

Notes

Red lentils will create a thicker, creamier soup, while brown lentils stay more intact. Sweet potatoes can become very soft after long cooking—cut them into slightly larger cubes if you prefer more texture. The soup thickens considerably as it cools, so thin with a little warm broth when reheating. Fresh lemon juice added at the end is essential for balancing the sweetness and spices.

Nutrition Information

Yield

Serving Size

1
Amount Per Serving Calories 183Total Fat 6gSaturated Fat 1gUnsaturated Fat 5gSodium 1212mgCarbohydrates 28gFiber 8gSugar 7gProtein 8g

The recipes and nutritional information on Yum Tonight are for informational purposes only. Always consult a healthcare provider for personalized dietary advice.

Recipe Tips and Tricks

Cut the sweet potatoes into similar-sized cubes so they cook evenly. Rinse lentils well and sort for any debris before adding to the slow cooker. For deeper flavor, quickly sauté the onions, carrots, garlic, and spices on the stovetop before adding everything to the slow cooker.

If your slow cooker runs hot, check the soup at the 6-hour mark. Stir in fresh lemon juice and herbs only after cooking to preserve their bright flavor. For a thicker soup, remove the lid during the last 30-45 minutes of cooking or mash some of the sweet potatoes and lentils with a spoon. Taste and adjust seasoning at the end, as slow cooking can mellow flavors.

Ingredients Notes

Red or brown lentils both work well—red lentils break down more and create a creamier texture, while brown or green lentils hold their shape for a heartier bite. Sweet potatoes bring natural sweetness, vibrant color, and extra nutrients. Extra virgin olive oil (or coconut oil) adds richness.

Onion, carrots, and garlic form a flavorful aromatic base. Warm spices—cumin, turmeric, coriander, and a hint of cinnamon—give the soup its cozy, slightly sweet-savory character. Vegetable broth keeps the recipe vegan and light; use low-sodium so you can season to taste.

Fresh ginger adds zing and warmth. Kale or spinach stirred in at the end adds color and freshness. Salt, black pepper, and a generous amount of fresh lemon juice brighten the finished soup beautifully.

Variations and Substitutions

Make it spicier by adding cayenne, chili flakes, or a spoonful of harissa. Swap sweet potatoes for butternut squash or carrots for a different natural sweetness. Add a can of chickpeas or coconut milk for extra creaminess and protein.

Stir in chopped spinach, kale, or Swiss chard during the last 30 minutes for more greens. For a smoky flavor, add smoked paprika or a teaspoon of liquid smoke. Use chicken broth if you’re not keeping it vegan.

Replace lentils with split peas for a thicker, more traditional split-pea style soup. Add diced tomatoes or tomato paste for a slightly tangy tomato-lentil version. Top with Greek yogurt, crumbled feta, or toasted pumpkin seeds for different textures and flavors.

Storage Options

Store leftover Slow Cooker Lentil Soup with Sweet Potatoes in an airtight container in the refrigerator for up to 5 days. The flavors improve wonderfully overnight. For longer storage, freeze in individual portions for up to 3 months.

Thaw overnight in the fridge before reheating. Reheat gently on the stovetop or in the microwave, adding a splash of broth or water if the soup has thickened too much. Stir in fresh lemon juice and herbs just before serving to refresh the bright notes.