1.Cut fish into small pieces.
2.Take 1/2 cup of water in a vessel and add the kudam puli for 5-10 minutes.
3.Grind together shredded coconut, chilly powder, turmeric powder, coriander powder, ginger, garlic and a small onion, into a smooth paste along with a little water.
4.Heat a vessel and add the above ground masala, fish tamarind, green chillies, enough water and salt.
5.Add cleaned fish when it is boiled.
6.Cover and simmer, until the fish is cooked through and tender.
7.Heat oil in a small frying pan.
8.Splutter mustard seeds.
10.Add the curry leaves and chopped small onions and fry, till they turn brown in colour.
11.Pour this into the cooked fish curry.