Sprinkle a handful of salt over the fish and clean thoroughly.
Prepare the homemade red chili paste.
Heat cooking oil in a saucepan and fry 1 medium onion chopped, chopped ginger & garlic, chopped green chilies, and curry leaves.
Then add chopped tomatoes and fry till it softens.
Add the 3 tbsp of red chili paste and fry for 2 minutes. Followed by tamarind water, salt, and 1 cup of water. (or add more water according to the desired consistency).
When the gravy starts boiling add fish pieces, chopped coriander leaves, and 3 tbsp of coconut oil.
Cook on medium-low heat for 10 minutes and then turn off the heat.
Let it remain covered for 1 hour before serving.