Wash the eggplants and pat them dry. Slit the eggplants length wise into fours but keep the stems intact. This way, the egg plants remain joined at the stem. Keep aside.
Heat a tspn of oil in a separate pan and add the cumin seeds, peanuts and cashew nuts and fry for a few seconds.
Add ginger, garlic and chopped onion and fry for a min.
Add the turmeric, coriander seeds, coconut and Kashmiri red chilies and fry till the mixture is brown. Allow the mixture to cool completely and blend to a fine paste using a little water and keep aside.
Heat oil in a thick bottomed pan and fry the egg plants till brown and tender, remove and keep aside.
Add the nigella seeds to the same oil and allow them to crackle. Stir in the curry leaves and fry for a few seconds.
Add the ground paste, tamarind pulp, salt and jaggery and mix well.
Add the sauted egg plants and 1/2 cup of water and cook covered over low heat till the egg plants are cooked through and soft.