1 medium-sized fish (e.g., snapper, bream, black fish)
1 large onion, quartered
0.8 tsp cumin powder
1½ tsp coriander powder
1½ tsp turmeric powder
½ tsp hot chilli powder (optional)
tamarind
oil for frying
salt and pepper to taste

Soak tamarind in a bowl of hot water, let stand to soften; squeeze and discard the seeds to make about ¼ to ½ bowl of tamarind liquid. (Alternatively, use 3 to 4 teaspoons of tamarind purée that can be purchased from Asian stores.)

Mix all ingredients (except onion) into a thick paste.

Cut flesh off bone on both sides of fish from top of fish and layer the paste on both sides of the inside of the fish. Set aside the left- over paste for the gravy.

Tie the whole fish from head to tail using a strong thread to keep the paste in.

Deep fry fish on both sides in hot oil. Place on serving dish. Cut and remove thread from fish.

Fry onion and, when lightly browned, add the rest of the paste and a little water and simmer for a while. Pour over the whole fish when ready to serve.