Peking duck is originally roasted in a closed oven (Chinese:焖炉), and Bianyifang is the restaurant that keeps this tradition. The closed oven is built of brick and fitted with metal griddles (Chinese:箅子;pinyin: bì zi). The oven is preheated by burning Gaoliang sorghum straw (Chinese:秫秸;pinyin: shú jiē) at the base. The duck is placed in the oven immediately after the fire burns out, allowing the meat to be slowly cooked through the convection of heat within the oven.Controlling the fuel and the temperature is the main skill. In closed-oven style, duck meat is combined well with the fat under the skin, and therefore is juicy and tender.