Soak the chilies in warm water for 10 to 15 minutes to soften. Then deseed and drain. Grind the chilies, belachan and shallots in a mortar or blender to a paste, adding a little oil if necessary to keep the blades turning.
Heat the oil in a wok over low heat and gently stir-fry the ground ingredients for 6 to 8 minutes until the oil surfaces.