Sōmen , somyeon, or sùmiàn are very thin noodles made of wheat flour, less than 1.3 mm in diameter. In China, it is also called guàmiàn. It is used extensively throughout East Asian cuisines. The most common example is Japanese sōmen and the noodles are usually served cold with soy sauce and dashi dipping sauce, similar to mori-soba (盛り蕎麦) noodles style. The difference between sōmen and another thin Japanese noodles hiyamugi (冷麦) are, hiyamugi is sliced by a knife to make them thin noodles but sōmen noodles are thinned by stretching the dough. The dough is stretched with the help of vegetable oil to make very thin strips and then air dried. When served warm in soup, usually in winter, they are called nyūmen (煮麺) in Japanese. Sōmen is typically high in sodium.