Soak tamarind in water and extract pulp. Clean and cut the fish to desired size.

Chop onions, garlic and tomatoes finely. Heat Oil in a Kadai. Add mustard, chana dal, urad dal, once it splutters, add chopped onions, curry leaves and garlic. Sauté well, fry till its golden in colour.

Add tomatoes, Chili powder, Coriander powder, Turmeric, cumin powder, methi powder and rock salt. Cook on high for few mins.

Then add tamarind pulp and required water. Cook on high for 5 mins. Simmer it and let it cook till the gravy becomes thick

Fish can be added once the gravy thickens and oil has come out. Cook on high flame for 5 mins after adding fish. Then simmer it for 5 mins. Add chopped green chilies and finely chopped coriander leaves at this stage. Once done, remove it from flame.

10 mins is enough to cook fish, else it will get shredded. Also the taste of the gravy changes based on the type of fish used.