Place the eggplants in an ovensafe dish large enough so it can hold the eggplants in a single layer. Sprinkle with some salt and half the turmeric. Drizzle 1 tsp of the oil, toss to coat, and place in a 400-degree oven for about 20-25 minutes until the eggplants are soft but not completely cooked.
Heat 1 tsp of oil in a saucepan. Add the cardamom, cloves, cinnamon, red chillies, coriander seeds, cumin seeds, fennel seeds and fenugreek seeds and toast until they start to get darker. Add the peanuts and toast until the peanuts start to get lightly golden. Remove to a plate.
Add the coconut to the skillet and toast, stirring constantly, just a few seconds until the coconut starts to get lightly brown. Don't leave the coconut on the stove unattended because it will burn in an instant.
Place the toasted spices and peanuts, coconut, jaggery, and the remaining turmeric in a blender. Add enough water and blend into a very smooth paste.
Heat the last 1 tsp of oil in the saucepan and add the mustard seeds. When they sputter, add the sliced onions. Saute them until they start to brown. Add the garlic and ginger and saute another minute.
Add the ground spices and when the come to a boil, add the eggplants. Add more water if the sauce is too thick.
When the sauce boils, turn down the heat so it just simmers, slap on a lid, and cook about 10-15 minutes or until the eggplant is really tender.
Add salt to taste. Garnish with some fresh coriander.
Serve hot with some chapatis, rotis, or with some dal and rice.