To the eggplant/brinjal make deep slits and roast it over the open flame. You can also roast it in the oven for that cut the brinjal in 2 pieces, brush oil over the surface exposed and bake in the oven @180 C/350F for 20-30 minutes. While at it please note that baking/roasting time will depend on the size of the eggplant. Bigger the eggplant longer it will take.
Once you have roasted the eggplant cool it and peel the skin off and mash it.
This is a kadhai/wok this is what I generally prefer to use.
So heat the oil in the pan and once the oil is hot add the methi seeds. Let the methi seeds sizzle but do not let them blacken as you dish will become bitter and nothing can fix it.
Immediately, add mustard seeds and cumin seeds. These will splutter.
Add garlic paste and sauté for the raw smell to go away then add the ginger and chili paste and stir.
Next, Add hing, turmeric powder, red chilli powder, dhania-jeera powder and mix well.
In this delicious aromatic mix add the mashed eggplant, boiled tuvar, salt, jaggery. Mix well and add some water, say about 1/2 cup.
Simmer over low heat for 10-15 minutes.
When ready to serve heat the gravy add 12-14 muthias and garam masala.
Mix well gently, cover and let the curry rest for 10 minutes.
Garnish with coriander and serve with rotis or rice.