Rub the fish with the coarse salt and leave for 30 minutes.
Preheat the barbecue or a griddle pan to medium-high.
Pour the rice, water and coconut milk into a saucepan
and bring to the boil. Reduce the heat to a simmer, cover with a lid and season lightly. Cook for 8 to 10
minutes, until the rice has softened. Remove the pan from the heat and drain any excess liquid.
Whisk together the shallot, ginger, fish sauce, vinegar,
soy sauce and caster sugar in a bowl. Add the mint and stir until thoroughly combined.
Wipe the salt off the fish, then brush with some of the
sunflower oil. Oil the ridges of thepan or barbecue and cook the fish for 10 to 12 minutes, turning once.
When the fish is cooked through, serve immediately
with the coconut rice and drizzle with the sauce.