Along with udon, soba is a staple food in Japan after rice
Soba is noodles made with buckwheat flour.
Soba noodles are made from dough of buckwheat flour, yamaimo (yam) and egg whites rolled out and cut into noodles. Wheat flour may be mixed in with the buckwheat flour, and the name varies depending on the wheat-buckwheat ratio. Examples are juwari-soba (also called towari-soba) made from 100% buckwheat and ni-hachi-soba made from 20% wheat flour and 80% buckwheat flour.
The most common way of eating soba is zaru-soba, or mori-soba, in which cooked noodles are rinsed in cold water, drained in a colander and dipped in a soba sauce made of soy sauce, sugar, mirin and dashi broth. Kake-soba is served warm with hot soup. There are many other ways of serving soba including soba with tempura, eggs, grated yamaimo and sweet cooked abura-age.