Take all the ingredients and keep it ready.
In a bowl add cleaned and washed fish, red chilli powder, turmeric powder, salt as required and 3/4 cup water. Keep it aside.
Heat oil in a mud kadai. add in mustard seeds and fenugreek seeds and let them sizzle. Then add crushed ginger and garlic. Saute for few seconds.
Now add chopped tomato and green chilly..
Cover and cook until the tomatoes become soft. Stir occasionally.
Then add the prepared spice water, do not add the fish now.
Add tamarind water. Bring it to boil for 5 minutes.
Now add the fish and combine well.
Add some curry leaves and chopped coriander leaves. Cook this partially covered for 5-7 minutes on medium high heat. The fish will be cooked on this time.
Now take it off the heat and cover with a lid. Let it sit for 2-4 hours for the flavors to develop. You can serve immediately as well. but it will taste wonderful if it sits for a while.
Serve this along with boiled tapioca and rice.