Char the eggplants: Wash and prick eggplants all over with a knife. Place directly over medium high gas flame (or on a grill). Cook, turning occasionally with tongs, until skin is completely blackened, cracked, and flesh is very soft; about 20-25 minutes.
Steam and peel: Transfer charred eggplants to a baking dish, cover with foil, and let cool for 20 minutes. Peel off the black skin (a few bits left are fine). Discard skin.
Purée the eggplant: Place peeled eggplant flesh in a food processor and process until smooth. Alternatively, mash well with a fork. Set aside.
Bloom aromatics: Heat oil in a large saucepan over medium heat. Add onion, garlic, and ginger. Cook until onion softens, about 3-4 minutes.
Toast spices: Add salt, coriander, cumin seeds, fenugreek, smoked paprika, ground chili, and turmeric. Stir and cook for 2-3 minutes until fragrant.
Simmer the dal: Add tomato paste, red lentils, water, and eggplant purée. Bring to a boil, then reduce heat to low. Simmer partially covered for about 25 minutes, until lentils are soft and creamy. Stir occasionally.
Serve: Taste and adjust seasonings. Serve over rice or with naan. Top with a dollop of dairy-free yogurt or coconut cream, and garnish with fresh herbs.