Clean the fish and marinate using turmeric, salt ,coriander and chilli powder for an hour.

Mix together fish, ginger, green chillies and tamarind water.keep it in the stove in medium flame.

Add enough water to cover the fish.

Close and bring to boil.

Shake the vessel inbetween so that fish doesnt stick to the bottom of the vessel.

:- Don`t stir using the spoon.

When curry becomes 1/3rd at approximately 10 minutes, add coconut paste .

close the lid and cook till the gravy sticks to the spoon(or thickens).

:- This is the right time to remove the vessel from stove.

Heat 1 tbsp of oil in a pan.Splutter mustard seeds and curry leaves in this oil.

Add it to th fish curry.

In remaining 1 tbsp of oil, fry the onion till they get a dark brown color .

Add it to the curry.Remember, the gravy should be still hot at this time.

Close the lid and let it stay for a while.At this time the flavor and smell of fried onion will spread inside.

Open, then stir or give the vessel a shake and serve.

:- You can make slight modfications here and there if you want.

Enjoy.