Preheat oven to 200 deg C.
Wash and cut fish if not using whole.
Using a sharp knife score the fish by making slits about 1 inch apart across the body of the fish. The Cut should be deep about halfway between the skin and the bone.)
In a medium-sized bowl, mix together pepper mix, garlic, thyme, salt, dry chilli, seasoning cube and fish seasoning. Sprinkle a little salt all over the fish, making sure to get into the slits and gut opening.
Do the same with 1 tablespoon of the seasoned pepper mix. Set aside.
Cut onions, potatoes and carrots into 1-inch chunks.
Cut bell peppers into long thin strips, julienned.
Put in the bowl of pepper mix and toss around to coat.
Cut out a piece of aluminium foil large enough to completely enclose the fish and vegetables. Place fish in the middle of the foil, place vegetables around and on top of it.
Drizzle with vegetable oil.
Wrap the fish and vegetables as tightly as possible so there is no leakage of both juices and steam.
Place the parcel in the oven and bake for 25-35 minutes, until the fish flakes easily and vegetables are soft enough.
Take out of the oven and leave to cool down a bit before opening.
To serve on a plate, gently slide the contents of the parcel onto the plate.