Gyudon (¥, gyūdon, beef bowl) is a popular domburi dish consisting of beef and onion served over a bowl of rice. The meat and onion are cooked in a mixture of soy sauce, mirin, sugar and sake giving the dish a sweet, salty flavour. Many chain restaurants (gyudon-ya) specialize in gyudon, making it an informal, inexpensive dining option frequented by students, and ideally suited to travelers on a budget.
Typically, pickled red ginger (beni shoga) and red chili spice (shichimi) are available at the table and added to taste. Tofu or konnyaku (devil's tongue) may be cooked along with the beef although these ingredients are more common in home recipes than at restaurants. Common restaurant additions are a beaten raw egg stirred into the finished product, or green onions sprinkled on top of the meat.
Gyudon-ya are numerous and often open 24 hours. These restaurants operate in one of two ways. Either a staff member takes one's order as in a common restaurant, or the meal is paid for in advance at a vending machine located near the restaurant entrance.
A side bowl of miso soup may come with the meal or be offered in a combo set. Other side dishes commonly available are salad and kimchi. Tea and water are offered for free with refill jugs available on the table for customers to serve themselves.