Soak the Mochai/dry beans overnight. Cook it to 4-5 whistles and keep it ready.
Roast shallots, fennel seeds, coriander seeds until shallots turn brown. Put in chopped tomatoes and coconut (either grated/sliced pieces) and saute until tomatoes are mushy. Switch off and add Sambar powder. Mix well and let it cool. Grind them to smooth paste.
Soak tamarind in water.
Heat oil in a cooker, crackle mustard seeds, Add chopped onions and saute until onions are brown. Saute in tomatoes until mushy.
Now, to this put in cooked mochai, tamarind water and ground masala. Add salt and little water. Cook it to 2-3 whistles in medium flame.