Cut slashes crossways in the fish and rub in the salt and then half of the lime juice. Set aside for 15 mins.
At the same time, whisk up the chillies, shallots, galangal and the remaining lime juice with 2 tbsp oil.
Cut a large piece of foil, place the shiny side down on a workbench and lightly brush with oil. Then place the fish in the centre and spoon a decent amount of the mixture on top. Tightly wrap and cook on a preheated BBQ (or ridged grill) for about 15 mins, turning once and keeping an eye on it.
Serve the fish with some cooking juices poured over the top and steamed rice and green vegies on the side.
