Fish Tamarind Gravy

Ingredients
Cat Fish 1 kg (after cleaning)
Medium size Onions 4 (ground)
Greenchillies 6 (cut length wise)
Tamarind (two fists)
Ginger_Garlic paste 4 tsps
Garam masala 4 tsps
Chilli powder 4 tsps
Turmeric powder
Butter milk or Curd
Salt to taste
Oil 200 gms
A whole bunch of fresh Coriander

Method
Soak the tamarind in 1/2 a glass of hot water for atleast 20 minutes. Make a puree of it. Meanwhile, cut the fish into fist size pieces and clean the pieces with some salt, butter milk or curd and turmeric powder (1/2 tsp) and then with water. Mix the fish pieces in a bowl with
chilli powder, 4 pinches of turmeric powder, salt and ginger-garlic paste.
Heat oil in a non_stick cooking dish and put the ground onion into it. Fry it on a medium heat till the onion becomes light brown. Now pour the tamarind puree, put the chillies into the dish. Empty the bowl of fish pieces into the dish. Add salt according to your taste. Let the gravy cook on a low heat. In between, keep moving the dish holding the sides of it to stir the contents.
A wooden spatula can be used by taking care that the pieces are not disturbed much. Add garam masala and finely chopped coriander 2 minutes before removing the dish from the flame. Those who do not like the gravy to be much hot and sour, they can reduce the quantity of chillipowder, garam masala and tamarind.