Tender beef fills silky steamed rice noodle rolls, finished with a drizzle of sweet soy. This protein-packed dim sum family favorite has a melt-in-your-mouth texture that's hard to resist.
In a medium bowl, thoroughly combine ground beef, cornstarch, white pepper, 1 tbsp light soy sauce, and sesame oil; mix until tacky and let marinate for at least 15 minutes.
In a separate large bowl, whisk together rice flour, tapioca starch, water, and 1 tbsp vegetable oil until smooth; let the batter rest for 10 minutes to reduce bubbles.
Lightly oil a flat heatproof dish or pan. Pour a thin layer of batter (just enough to cover the bottom) and steam over high heat for 3 minutes, until partially set.
Scatter a quarter of the marinated beef and some scallions evenly over the surface, then cover and steam on medium-high for 2 minutes, until the beef turns opaque and the rice sheet is firm.
Using a thin spatula, gently roll the noodle sheet while hot; transfer to a plate. Repeat with remaining batter and filling, oiling the pan as needed.
For the sauce, in a small saucepan, combine 2 tbsp light soy sauce, oyster sauce, sugar, and 1/4 cup water. Bring to a gentle boil over medium heat, stirring until sugar dissolves. Let cool slightly.
Drizzle the sweet soy sauce generously over the assembled rolls just before serving. Enjoy warm.