Wash and keep the Avarekalu. Wash and peel the skin of potato. Chop into 4 big pieces. Wash and cut brinjal into chunks.
Pressure cook avarekalu,chopped brinjal & Peeled, chopped potato adding required water & salt. Set aside.
Soak tamarind in a cup of water. Brush the onion with oil. Burn the whole onion(with skin) over direct flame. Use a tong & hold the onion. Roast it all the sides in low to medium flame. When the skin of onion turns black, remove & let it cool.
Similarly roast the greased whole garlic bulb on all sides till its skin turns black.( Refer Notes for variations)
Peel the outer skin of garlic & onion. Grind it to a smooth paste adding soaked tamarind, coconut, chilli powder, turmeric powder, dhania powder and coriander leaves. Mix this paste with the cooked avarekalu, potato & brinjal pieces. Check for consistency & taste and add some water or chilli powder, dhania powder if needed.
Let the gravy boil for few minutes. Gravy will thicken as it boils. Switch off the flame & temper mustard seeds, cumin, urad dal & curry leaves. Add to gravy and mix well. Enjoy !