Cook both green gram and bengal gram dhal together till it is soft.
Cut the brinjal into small size pieces and put it in a thick bottomed vessel. Pour water just to cover the vegetable. Add sambar powder, turmeric powder and salt. Cook on medium flame till the brinjal is soft.
Meantime, grind coconut gratings, green chillies and jeera together to a coarse paste.
When the brinjal is cooked well, add the cooked dhal and the coconut paste and mix well. Allow to boil for few minutes.
Season it with mustard, onion chopped finely and curry leaves.