Cut the fish into medium size pieces. Wash it and add turmeric powder and keep aside. Put tamarind into ½ cup of water. Sprinkle water into the grated coconut and transfer the content into a mixer grinder. Run it for 1 min without adding water and make a thick coconut milk. Tip: (Sprinkle hot water instead of normal water for better results) Also note that the thick coconut milk is for garnishing purpose. Now keep this thick gravy aside and add more water into the grated coconut and grind it for 2-3 mins. Prepare 1 cup of coconut milk from this.
Heat the kadhai or pan and pour oil. Add chopped onion and fry it till golden brown. Keep this aside. Now add fish into the kadhai and add tamarind mixture and salt. Cook it for 5 mins. Now add fried onions, green chilies, chopped ginger, black pepper, red chilly powder and coriander powder. Pour coconut milk into this. Add salt as required. Close the lid and cook it for 15 mins. Don’t forget to check the taste in between. When the gravy is getting thick add the thick coconut milk into this and stir well for a min.
Garnish your dish with coriander leaver or curry leaves. Serves hot with Veg Pulav or Steamed Rice.