Hung Yen: Tuong Ban (Ban soya sauce) has been a delicacy of northern Vietnam since the end of the 19th century. It is a delicacy found in Ban Yen Nhan Ward in My Hao Town, Hung Yen province.

According to Vietnam News Agency, Ban soya sauce has maintained its presence and popularity through generations in this region. The sauce is known for its unique taste and traditional production methods, which have been passed down through families in the area. The process of making Tuong Ban involves fermenting soybeans, which gives the sauce its distinct flavor. This traditional craft not only serves as a culinary delight but also represents a piece of cultural heritage for the people of Hung Yen.