Thai Garlic-Basil-Chili Sauce

2 to 4 Thai finger peppers
4 cloves garlic
2 tablespoons fish sauce
2 1/2 tablespoons soy bean sauce
1/2 tablespoon black bean sauce
2 tablespoons sugar
1 1/2 cups water
1 1/2 tablespoons canola oil
1/2 ounce sweet basil leaves
1/2 tablespoon cornstarch

Pound pepper and garlic in a mortar.
Heat oil in a wok. Stir-fry pepper and garlic mixture, until it starts to cook. Add fish sauce, soya bean sauce, oyster sauce, black soy sauce, sugar, and water. Continue to stir-fry until it comes to a boil.
Add cornstarch to thicken the sauce. Add sweet basil leaves.