Steps
1. Clean, wash and slice the pomfret, then marinade in salt and lemon juice for 60 mn.
2. Blend the tamarind in 1 cup of water
3. Slit and halve the chillies. Slice the onion and chop fine the ginger.
4. Mix the sliced onion, ginger and green chillies with the tamarind juice. Add the cubed mango.
5. Add the Spice Paste and 2 cups of water. Cook in a pan on a low flame till the curry begins to boil.
6. Simmer for about 15 mn. Add the fish and cook for another 10 mn Do not cover the pan. Serve hot with boiled rice.

Source
Personal information, Recipes from GOA, West Coast of India