Step 1

Wash the fish under cold running water. Pat dry with paper towel inside and out. Use a sharp knife to cut 3 slashes, about 5cm long and 1cm deep, in the thickest part of the fish on both sides. Season with salt.

Step 2

Preheat a barbecue or chargrill on high. Brush fish with oil. Cook on grill for 8 minutes each side or until fish flake easily when tested with a fork in the thickest parts.

Step 3

Meanwhile, combine tamarind and boiling water in a heatproof bowl. Set aside for 10 minutes to soak. Strain through a fine sieve into a jug. Discard seeds and pulp. Add sugar and fish sauce, and stir to combine.

Step 4

Place fish on serving platters. Drizzle with tamarind sauce and sprinkle with chilli. Serve immediately.