Heat the 2 tablespoons oil over medium-high heat in a large skillet, and fry eggplant pieces until golden, about 5 minutes. Remove the eggplant from the skillet and set aside; wipe out the skillet with a paper towel.
Heat the 6 tablespoons oil in the same skillet over medium heat. Stir in the cumin, fenugreek, kalonji, and sesame seeds, and cook until the cumin turns golden, about 2 minutes. Reduce the heat; stir in the ginger and garlic, and cook for a few seconds. Stir in the onions and green chile pepper, and continue to cook and stir until the onion is golden, about 10 minutes.
Stir the tomato puree, chili powder, coriander, turmeric, and salt into the onions. Cook and stir over medium heat for 2 minutes, or until the oil separates. Stir in the cooked eggplant; cover and simmer until eggplant is tender, about 5 minutes. Pour in the coconut milk; stir until blended and heated through. Sprinkle with cilantro leaves.