Heat oil in a deep bottomed vessel, add mustard seeds, fenugreek seeds and asafoetida. Let them splutter.
Add the chopped onions and green chilli and fry them until they are brown.
Meanwhile, pressure cook bottle gourd and drumstick for one whistle with little water.
When the onions are brown, add the coriander powder, cumin powder and chilli powder.
Add the chopped tomatoes and fry until they are soft.
Add the pressure cooked vegetables to it and also add the squeezed out tamarind juice and sugar.
Boil this gravy until the tamarind juice is cooked.
Garnish with coriander leaves.