Wash and slit eggplants into quarters without slicing all the way through (see picture). Keep soaked in water for 30 mins while you prepare the masala.
Dry roast peanuts and sesame seeds. Keep aside.
Dry masala: In a tbsp of oil, roast channa dal, urad dal, red chillies, corriander seeds if using (instead of powder), mustard, cumin and curry leaves until the dals turn slightly brown.
Grind together the above roasted dry masala along with grated coconut, tamarind paste, turmeric powder, jaggery, hing, salt and 2 chopped onions. Add corriander powder if using (instead of seeds). Add as much water as needed to get a semi solid paste (about 1/4 cup water). The ground masala should not be watery.
Mix the remaining chopped onions to the ground masala.
Stuff this masala into the slit eggplants.
In a skillet / wok / karahi, heat oil and place stuffed eggplants in one level.
Add required amount of water (anywhere from 1-2 cups) to left over masala and pour over the eggplants.
Cook till eggplants are done turning over every 5-7 minutes Takes about 50-60 minutes Add another 2-3 tbsp oil if required.