Subway Samseongjeom in Seoul is a sandwich shop where you choose the bread, length, vegetables, and sauces. A common order adds tuna and egg mayo on flatbread with sweet onion sauce, and a 15cm sandwich is enough for a meal. At lunch, orders are handled quickly even with about 10 people in line, and seating is roomy for the size of the store. During lunch hours, office workers crowd in and the store gets busy.