Take Onion, Cumin and Fennel in a mixer and grind to a smooth paste.
Grind coconut into a paste.
Heat oil in a heavy bottom pan and fry the onion paste that we prepared. Adding gingelly oil will enhance the flavor
Once the raw smell leaves, add tomatoes along with chilli and salt. cover and cook till tomatoes turn mushy.
Once the tomatoes are done, add the powdered spices. Add turmeric, coriander, and chilli powder and fry for a while.
Then, add tamarind water and allow it to boil.
When the tamarind water boils, add the coconut paste. Half cover the pan and cook till the gravy thickens
Once the gravy thickens, add fish pieces and cook for just 5 minutes.
For Seasoning, pour oil in a frying pan and season with the given ingredients. Add this to the broth and the delicious fish curry is ready.