Roast a big brinjal on a stove top or oven. Keep turning for even roasting from all sides.
Put the brinjal in a bowl and keep it covered. On the same stove top roast chilli and tomato.
Once roasted transfer them into a bowl and cover for 5 minutes. After 5 minutes peel off brinjal,chilli and tomato.
Chop chilli and tomato into small pieces. Cut the top of brinjal and mash rest with a fork.
Heat a pan and add mustard oil, once oil is hot add in chilli and asafoetida and mix.
Add ginger, garlic and roast it well next add in onion and cook till it turns golden brown.
Once onion is done add in roasted chopped chilli, roasted tomatoes and sauté for a while.
Cover the pan for 2-3 minutes and cook till mixture is soft but stir a couple of times.
Add in turmeric powder, Kashmiri red chilli powder for colour, mix and sauté till mixture is ready.
Add in mashed brinjal, give it a good mix and fry for 5-6 minutes. Now cover and cook for 5 more minutes on low flame.
Garnish with coriander leaves.