Cheung fun (肠粉, literally intestine noodle — the shape of a rolled rice noodle roll resembles a sausage casing) is one of the most technically demanding dim sum preparations: a very thin sheet of fresh rice noodle steamed on a cloth-lined tray or in a special stainless steel drawer, then wrapped around a filling (beef, shrimp, char siu, or egg) and served with sweet soy sauce, sesame sauce, and oyster sauce. The excellence of cheung fun depends entirely on the quality and freshness of the rice noodle — it must be steamed and served immediately, as the noodle toughens within minutes of leaving the steamer.
The rice noodle batter: 150g rice flour, 30g wheat starch, 20g tapioca starch, 500ml water, 1/2 tsp salt, 1 tbsp neutral oil. Mix to a smooth, pourable batter. Rest 30 minutes. The batter should be very thin — slightly more viscous than water. The steaming method: Lightly oil a flat stainless steel drawer or tray. Pour a thin layer of batter (2-3mm). Add the filling across the width. Steam 2-3 minutes over rapidly boiling water until the noodle is set and becomes slightly translucent. Use a spatula to roll the noodle away from the near edge, wrapping the filling inside. Slide onto a plate. The sauce: Sweet soy sauce (lightly sweetened dark soy), sesame sauce, oyster sauce applied to the serving plate.
Batter too thick: The noodle sheet becomes rubbery. The batter must be extremely thin. Not enough steam: The steam must be at full power.
Fuchsia Dunlop, Land of Fish and Rice (2016); Eileen Yin-Fei Lo, Mastering the Art of Chinese Cooking (2009)