Pyeonsu

Pyeonsu (Korean: 편수) is a square-shaped mandu (dumpling) in Korean cuisine. It is a food typically served in summer, served chilled, and dipped in soy sauce and vinegar. The city of Gaeseong is famous for its pyeonsu.

The origin of the word (편수) is obscure. Some claim that it was derived from (변시), which appears in the 1527 book Collection of Characters for Training the Unenlightened as a borrowing from the Old Mandarin Chinese (匾食, ) that meant "dumplings" at the time. In Korean royal court cuisine during the Joseon era (1392–1897), wheat-skin dumplings boiled in water were called (), with the letters (; meaning any flour dough food) and (; meaning "spoon") which, combined, could refer to dumplings that are eaten with a spoon. Another claim is that the word was derived from (), which means "Byeon's dumplings", because it was first made by a person whose family name was ().

Although Korean mandu are believed to have first been brought to Korea by Yuan Mongolians in the 14th century during the Goryeo, the variety pyeonsu is thought to be derived from Ming Chinese dumplings brought into the Korean peninsula by the Joseon merchants based in Gaeseong.

Wheat flour dough is made by mixing wheat flour with boiling water. The dough is then rolled thin and cut into squares to make pyeonsu. Common fillings include meat and vegetables such as beef, pork, chicken and pheasant meat, tofu, mung bean sprouts, mushrooms, oyster, and a couple of whole pine nuts per dumpling. The stuffings are seasoned with salt and black pepper, ground toasted sesame, sesame oil, and minced aromatic vegetables such as scallions, ginger, and garlic.