1.Preheat oven to 200°C (180°C fan-forced). Place a large piece of extra wide foil on the bench and top with a slightly smaller sheet of baking paper, ensuring that both are larger than the fish in length.
2.Rinse the fish under cold water and pat dry with absorbent paper. With a sharp knife, make 4 deep diagonal incisions across the flesh on both sides.
3.Combine the oil, ginger, lemongrass, rind, 2 tablespoons of the juice and pepper in a small bowl; season with sea salt. Rub the flavoured oil all over the fish, the incisions and inside the cavity.
4.Cover with another piece of baking paper and foil and scrunch the edges together to seal the fish within. Carefully lift the parcel on to a large oven tray. Bake fish for 30-35 minutes or until just cooked through.
5.Meanwhile, place sugar and ¼ cup (60ml) of the water in a small saucepan over a medium-high heat; stir, without boiling, until sugar is dissolved. Raise the heat and cook until the syrup starts to turn light golden brown. Add the chilli flakes, fish sauce, remaining lime juice and remaining 1 tablespoon water. Remove from heat and stir to combine.
6.Open the fish parcel. Carefully lift the fish on to a serving platter and scatter with sprigs of coriander and sliced chilli. Drizzle with the chilli sauce and serve with the lime wedges and steamed jasmine rice, if desired.
Not suitable to freeze or microwave. To test if the fish is cooked, insert a knife into the thickest part – the flesh should no longer be translucent and flake easily.Note