Noodles are foods made from wheat, rice, starch, buckwheat, oat or other meal, mixed into a dough or batter, formed into strands or sheets, and boiled, tossed, stir-fried or dried for keeping. The methods include pulling, cutting and shaving, rolling and cutting, extruding, steaming sheets and cutting them into strips, and hang-drying, giving pulled noodles, knife-shaved noodles, dried hung noodles, rice noodles, liangpi, starch vermicelli and instant noodles. They are eaten in soup, tossed or stir-fried, and each region has its own style shaped by local produce and taste. Millet noodles about four thousand years old were reported from the Lajia site in Qinghai; the Hou Han shu mentions boiled dough (zhubing) under the Eastern Han emperor Zhi; and the Northern Wei Qimin yaoshu gives methods for shuiyin and botuo.