Add sliced onions, ginger, and garlic to the pan.

Stir frequently and cook until onions turn soft and translucent.

Add chopped tomatoes and sauté briefly.

Add raw mango or tamarind paste and ½ cup water.

Cover and cook until the mixture softens and lightly thickens.

Sprinkle in salt, turmeric powder, and Kashmiri red chilli powder.

Mix well and cook briefly to bloom the spices.

Gently place fish slices into the pan.

Pour in coconut milk and the remaining 1 cup of water.

Shake the pan gently (do not stir) and simmer until the fish is cooked through.

Taste the curry and adjust salt if needed.

Switch off the heat and let it rest briefly.

Serve hot with rice or appams.