Stuff the cavity of the snapper with the basil leaves and set aside.
Heat the peanut oil in a large frypan over high heat until it begins to smoke. Place the snapper in the frypan, and quickly brown on both sides, about 1 minute total. Place the fish into the roasting pan, and sprinkle with fish sauce. Reserve the peanut oil in the frypan.
Bake fish in preheated oven until the flesh flakes easily with a fork, 25 to 30 minutes.
Meanwhile, heat the remaining peanut oil in the frypan over medium heat. Stir in the garlic, ginger, chillies and yellow capsicum and cook until the capsicum has softened, about 5 minutes.
Stir in the sugar, rice vinegar, water, and tomatoes.
Bring to a simmer over medium-high heat until thickened to desired consistency. Pour the sauce over the snapper, and garnish with extra basil leaves to serve.
Altered ingredient amounts.
I used Spiced Caramelised Red Wine Vinegar instead of rice vinegar (from this company http://www.thegrapealternative.com.au/) & added 1 cup of coconut milk to the sauce. Also served with white & wild rice cooked in coconut milk. DELICIOUS! - 03 Mar 2011