First Grind coconut and green chillies together to a smooth paste by adding some water..Set this aside for a moment..

Heat oil in a kadai..Add in mustard seeds and cumin seeds,let it splatter.

Now add in onions and fry for 2 mins..Add in brinjals and mix well..

Now add in chilli powder and coriander powder and mix well.

Pour in the coconut paste and stir to combine..Add in salt and jaggery and mix well..

Pour in tamarind water and bring this to boil..

Cover and simmer for 15-20 mins until oil floats on top..

Serve hot with rice..