Mian Cha, or seasoned flour mush, has nothing to do with tea though it sound like a tea in Chinese. It is actually a kind of very thick porridge made of millet and rice flour. Like afternoon tea in the Western customs, Mian Cha is usually served in the afternoon.

The dish is prepared in two steps. First, flours of sorghum and/or millet are cooked in advance, often stir fried, and after the completion, the flour is ready to be served. When a customer orders the dish, hot water is poured into the bowl containing the flour(s) to create a paste-like mush, and it is served with white and/or brown sugar, and Sweet Osmanthus sauce. Interestingly, the Sweet Osmanthus plant is not native to northern China.

Traditionally, the skill of the server judged on several factors and one of them is the requirement is regarding the resulting mush: the most skillful server would be able to create the mush that is so thick that when a chopstick is inserted into the mush, it remains vertical, while at the same time the mush remains fluid. Other criteria for the servers' skills included the ability not splash any hot water outside the bowl and spill out any flours, because traditionally all ingredients are placed in a bowl, into which is poured boiling water from a special copper kettle with a long, dragon-shaped spout called and special skills were needed to handle this equipment. The ingredients are then stirred together and the chatang is eaten with a spoon.

Traditionally, chatang vendors were easily distinguished by the kettle they used. The kettle was extremely large, up to four feet tall with a diameter in excess of a foot, and was often made of copper. There are two kinds of kettles: those used by street vendors, and those found in restaurants and tea houses. The two differ in internal structure.

The kettles used by street vendors have a more complex internal structure. They are double layered, with fuel in the inner layer in the center, and water in the outside layer. The advantage of such a structure is that it reduces the need to carry a stove to heat the water in the kettle, and it improves fuel efficiency since most heat is utilized, in contrast to the use of a separate kettle and stove. Furthermore, in the windy weather conditions of northern China, such a structure prevents the flame from being blown out by the wind if there are separate ordinary stovetop kettle and stove.

Despite the two varieties of kettles' identical external appearance, the complex structure of the kettles used by street vendors is not present for those used in restaurants and tea houses, for obvious reasons: since the stove is located inside, it is immune to the windy weather outside and stoves are necessary to cook other dishes, so there is no need to pay extra for a more expensive kettle with such a complex structure.