This Japanese dish can be made with soba noodles, also known as buckwheat noodles, or chuckamen noodles, which are made from wheat flour. The latter are the most common noodles in traditional Japanese ramen. On mainland Japan, thinly sliced pork is the most common protein source used; in Okinawa, ham is a popular choice. In addition to the meat and noodles, thinly sliced vegetables are cooked in the dish; onion, cabbage and carrots are the most common.