If mincing the beef by hand, first slice the beef into thin steaks, then into long strips, and finally into small cubes. Using a cleaver or large knife, mince until the pieces are about the size of ground beef or slightly larger.
3-4 oz beef
Slice the scallions thinly and set aside. You'll be adding this along with the beef onto the steaming rice roll, as well as using it for garnish.
4-5 stalks scallions
Into a small bowl, add the minced beef and beef marinade ingredients, except for the water. Mix everything thoroughly together, then add the water at the end and mix again. The water added and absorbed into the meat here helps provide a tender texture.
1/2 tbsp minced ginger, 1/2 tsp soy sauce, 1/2 tsp oyster sauce, 1/2 tsp Chinese cooking wine (Shaoxing), 1/2 tsp cornstarch, 1/2 tsp neutral oil, 1/4 tsp sugar, 1/4 tsp sesame oil, pinch of salt, dash of white pepper, 1/2 tsp water
For the rice roll batter, mix together the dry ingredients first: rice flour (not glutinous rice flour), potato starch, tapioca starch, and salt. Gradually add the water to the batter and mix very thoroughly with a whisk. Add neutral oil, mix again, and set aside.
40 g rice flour, not glutinous rice flour, 30 g potato starch, 10 g tapioca starch, 300 ml water, 1 tsp neutral oil, 1/2 tsp salt
For the rice roll sauce, mix together hot water, sugar, light soy sauce, sesame oil, and oyster sauce until sugar dissolves.
1/4 cup hot water, 1.5 tbsp soy sauce, 2 tsp sugar, 1/4 tsp sesame oil, 1/2 tsp oyster sauce