Cook's Tip: I recommend mixing the following dry spices before starting cooking: 2 teaspoons ground coriander, ½ teaspoon ground cardamom, ½ teaspoon cinnamon, ½ teaspoon fenugreek, 1 teaspoon smoked or regular paprika, ¼ teaspoon nutmeg, 1 teaspoon salt, and ¼ teaspoon black pepper. Set aside.
Heat a Dutch oven or medium soup pot to medium-high heat and add 1 tablespoon of cumin seeds. Toast the seeds, stirring constantly, for about a minute until they become fragrant.
Add the red onion. Sauté until the onions soften (2-3 minutes). If they start to stick, add water a tablespoon at a time.
Stir in the garlic, then add the rest of the spices, 2 tablespoons sriracha or chili paste, and the tomatoes. If necessary, use the back of a wooden spoon to break up the tomatoes.
Add the vegetable broth and stir everything, including the bottom of the pot. Mix in the lentils.
Cover the pot and cook for 15 minutes, until the lentils are tender and the dal is thick and creamy. If the dal is too thick, add more vegetable broth or water.
Serve with rice and garnish with chopped cilantro, lemon wedges, sliced green onions, or finely chopped red onions.