Few foods do a better job of warming you to your core than a hearty lentil soup. Come fall, lentils are always on heavy rotation in my house - not only because they’re hearty and healthy, but they’re also affordable and easy to cook. In this lentil soup, I add toasty Indian spices, creamy coconut milk, plus kale and sweet potato for extra nutritional oomph. Feel free to follow this recipe to a T (it is a good one), or make it your own. Just be sure that you have the key components: a healthy fat, aromatic vegetables, spices, lentils, a neutral cooking liquid like stock, and a touch of acidity from citrus or vinegar to keep it bright. Within that, you can add sturdy greens, squash, root vegetables, fresh herbs or a creamy finish from coconut milk, cream or Greek yogurt. Lentil soup is what you make of it and I promise it will always satisfy.
In a large enameled cast-iron casserole, melt the coconut oil. Add the onion, celery and carrot and a generous pinch of salt and cook over moderate heat, stirring occasionally, until translucent, 5 to 8 minutes. Add the sweet potato, ginger and garlic and cook, stirring, until fragrant, 2 to 3 minutes. Add the cumin, fennel seeds, turmeric, crushed red pepper, cinnamon and lemon zest and cook, stirring occasionally, until the spices smell toasty, about 2 minutes more.
Add the lentils, vegetable stock, 2 cups of water and a generous pinch of salt and bring to a boil. Reduce heat to low and cook partially covered, stirring occasionally, until the lentils and sweet potato are tender, about 25 minutes. Discard the strips of lemon zest. Stir in kale, coconut milk and the lemon juice and cook until the greens are just wilted, about 5 minutes. Season with salt.
Ladle the soup into shallow bowls and garnish with cilantro. Serve with crusty bread for dipping.