The Chinese barbecue pork often used in dim sum is called char siu. It is a Cantonese-style roasted pork known for its glossy surface, reddish color, and sweet-savory flavor.
Char siu is a type of siu mei, the Cantonese tradition of roasted and barbecued meats. Long strips of pork are marinated with seasonings such as maltose or honey, Chinese rice wine, five-spice powder, soy-based sauces, and sometimes fermented red bean curd. The meat is then roasted, traditionally suspended from forks, which explains the name's association with fork-roasting.
In dim sum, char siu is especially famous as the filling in cha siu bao, a steamed or baked barbecue-pork bun. It also appears in rice noodle rolls, pastries, noodles, and rice dishes. The pork cut can vary; shoulder, belly, loin, and highly marbled neck meat are all used.
Char siu should not be confused with siu yuk, which is Cantonese crispy roast pork, or Japanese chashu, which is usually rolled pork belly braised for ramen rather than Cantonese-style roasted pork.