Add Oil to the pan. Sautee the brinjal till it is half cooked. Remove the brinjal from the pan.
Cut one onion to fine pieces. Add mustard to the pan and once it crackles, add the onion and sautee it till the onion is transparent.
Add the roasted peanut powder, chilli powder, tamarind juice, jaggery, salt and garam masala to the pan. Add some water. Keep sauteing it till the smell of the chilli powder goes away.
Now add the cooked brinjal to the pan and keep cooking till mix gets cooked.