Spinach and Tomato Dal (Indian Lentil Soup)

Bring 4 cups of water and lentils to a boil in a saucepan, adding salt. Lower the heat to medium-low and simmer for 10 minutes. Skim off any foam, then continue simmering until lentils are tender, about 1 hour.

In a separate saucepan, heat oil and add mustard seeds and cumin seeds. Cook for 2 to 3 minutes until they begin to splatter. Add the onion, garlic, and turmeric, and cook, stirring occasionally, until the onion softens, about 5 minutes. Stir in the spinach, tomatoes, and cayenne pepper, cooking until the spinach wilts and the tomatoes soften, about 5 minutes.

Combine the cooked lentils and cilantro with the spinach mixture, bringing everything to a simmer. Cook for 5 more minutes. Taste and adjust the salt and water to suit your preferences.