Mix up the ingredients for the sauce and adjust according to your preferences. Preheat the oven to 200C/400F.
Place your fish fillet, skin side down if applicable, on a medium-large rectangle of baking paper atop a shallow baking dish. This will help prevent any spillage as you fold because the dish edges will cup the baking paper (only important if you add the sauce prior to cooking).
Arrange the fish so that both the fillet and rectangle are facing towards you.
Season with salt and pepper and rub the seasoning into the fish.
Add the remaining flavourings for the fish. You can add the sauce here or after baking – I like to add it before baking but see what you prefer.
Take the left and right sides of the baking paper and bring them together over the fish. Begin to tightly roll them together, folding as you go, until the rolled paper is flush with the fish. Take the top and bottom ends of the paper and roll them away from the fish a few times to seal off the open seam, then tuck them tightly underneath the fish. The weight of the fish will hold them down.
Bake for 20-30+ minutes, depending on the thickness of your fish fillet. This method makes it hard to overcook the fish and you can always pop it back into the oven if the centre isn’t done.
Once baked, remove from the oven, check for doneness and serve over a bed of rice. Add the sauce here if you haven’t already. I like to serve my fish with white rice, sauteed Asian greens, chopped peanuts and some coriander.