Chop the onion, carrots, celery, bell pepper, and sweet potato into fairly even pieces so they cook evenly. They don’t need to be perfect—just roughly the same size.
1 medium yellow onion, 2 medium carrots, 2 ribs celery, 1 medium red bell pepper, 2 cups sweet potatoes
Place the dry lentils in a fine-mesh strainer and rinse under cool running water. Pick out any small stones or debris.
1 1/2 cups dry brown or green lentils
Add the rinsed lentils, onion, garlic, carrots, celery, bell pepper, sweet potatoes, frozen green beans, and frozen peas to the slow cooker. Pour in the diced tomatoes with their juices, coconut milk, vegetable broth, and tomato paste. Stir gently to combine; the mixture will look brothy but will thicken as it cooks.
1 1/2 cups dry brown or green lentils, 1 medium yellow onion, 3 cloves garlic, 2 medium carrots, 2 ribs celery, 1 medium red bell pepper, 2 cups sweet potatoes, 1 cup frozen green beans, 1 cup frozen peas, 1 can diced tomatoes, 1 can full-fat coconut milk, 4 cups vegetable broth, 2 tablespoons tomato paste
Stir in the olive oil, cumin, smoked paprika, dried oregano, turmeric, chili or curry powder (if using), salt, and black pepper. Make sure the tomato paste is fully mixed into the liquid so the flavors are evenly distributed.
2 tablespoons olive oil, 1 1/2 teaspoons ground cumin, 1 teaspoon smoked paprika, 1 teaspoon dried oregano, 1/2 teaspoon ground turmeric, 1/2-1 teaspoon chili powder or mild curry powder, 1 1/4 teaspoons fine sea salt, 1/2 teaspoon black pepper
Cover the slow cooker and cook on LOW for 7–8 hours or on HIGH for 3 1/2–4 1/2 hours, until the lentils are tender but not falling apart and the sweet potatoes are very soft when pierced with a fork. If the stew is too thick, stir in a splash of broth or water; if it’s too thin, remove the lid for the last 20–30 minutes to reduce.
Once the lentils are tender, stir in the chopped spinach or kale, if using, and cook on LOW for another 5–10 minutes, just until the greens are wilted and bright. Turn off the slow cooker and stir in the lemon juice. Taste and adjust seasoning with additional salt, pepper, or red pepper flakes if desired.
1 tablespoon fresh lemon juice, 2 cups baby spinach or kale, red pepper flakes
Serve the stew ladled over warm rice, quinoa, or on its own in bowls. Garnish with fresh herbs, avocado slices, or a spoonful of coconut yogurt, and additional lemon or red pepper flakes if you like.
cooked rice, quinoa, or cauliflower rice, fresh cilantro or parsley, red pepper flakes, sliced avocado or coconut yogurt