What is "gyudon"?

Gyudon is a popular Japanese dish that consists of a bowl of rice topped with thinly sliced beef and onions that have been simmered in a sweet and savory broth made from soy sauce, mirin, and sake. The dish is often garnished with sliced scallions and served with a raw egg that can be mixed into the rice and beef to create a creamy texture. Gyudon is a quick and filling meal that is often enjoyed for breakfast, lunch, or dinner in Japan. It is also a popular dish in Japanese fast food chains and can be found in many restaurants and food stalls throughout the country.