Crystal powder is a vermicelli made from sweet potato as the main raw material, but it is different from ordinary sweet potato powder. Because potato flour and mung bean flour are also added, the vermicelli made from it is more crystal clear. In terms of cooking techniques, traditional Hunan cuisine is adopted, which has a sour, fresh, fragrant and spicy taste. From the processing to the dishes, this kind of vermicelli is unique to Fire Palace and is difficult to eat in other places.