Preheat your barbecue or light the charcoal. Gut the fish, remove the scales, and wipe it well. Make 3-4 vertical, to the bone incisions on each side of the fish. Brush the fish, in and out, with olive oil. Season with salt and pepper, in and out. Put in the fish's belly some fresh herbs and slices of lemon or orange. Put slices of ginger in the incisions you made earlier.
Place the fish in a baking pan. After the bbq is ready or after the grill has warmed up well, bake for 5-7 minutes and then turn it on the other side for another 5 minutes.
For the sauce, place a small saucepan on medium to high heat. Add the olive oil and when it's heated up, add the garlic and the chili peppers. Cook for 30 seconds. Add the soy sauce and sugar and allow to boil for 1 minute.
Pour the sauce over the fish and serve with slices of lemon.