II
The Method
1
Combine the flour, instant yeast, and sugar in a large bowl. Add 260–270 ml warm water gradually, mixing until a shaggy dough forms. Turn out and knead until the surface is smooth and the dough springs back when pressed — roughly 8–10 minutes by hand. Return to the bowl, cover, and rest for 1 hour. The dough is ready when it has doubled in volume and a finger pressed into it leaves a hole that does not spring back.
2
Turn the risen dough onto a lightly floured surface. Roll into a thin rectangle of approximately 30 × 40 cm. For the scallion-and-oil version, brush the entire surface evenly with sesame oil or neutral oil, then scatter the finely chopped scallion and salt across it. For the sesame-paste version, spread the diluted sesame paste evenly, then scatter salt and black sesame seeds. The filling must reach edge to edge. The sheet is ready when the surface looks uniformly glossy and aromatic.
3
Fold the rectangle into thirds as one would fold a letter: bring the bottom third up, then fold the top third down over it. Cut the folded block into strips approximately 3 cm wide. Each cut should reveal clean, distinct layers of dough and filling.
4
Stack two strips together with their filling layers facing in the same direction. This is where the dish lives or dies: press a chopstick firmly down the full length of the centre of the stacked strips, compressing the layers together so they will hold their shape through twisting and steaming. Hold the two ends and twist them in opposite directions. Stretch the roll slightly, then fold the ends underneath to form a compact oval. A well-shaped roll holds its twist without unwinding and shows the layered cross-section clearly at each end.
5
Place the shaped rolls on squares of parchment paper in a steamer basket, spaced to allow expansion. Rest for 15–20 minutes. The rolls are proofed when they appear visibly puffed and feel slightly lighter and airier to the touch.
6
Bring the steaming water to a full, rolling boil before loading the basket. Steam over boiling water for 12–15 minutes with the lid firmly on. Do not lift the lid during steaming. At the end of steaming, turn off the heat and leave the lid on for a further 2 minutes before opening. The rolls are done when the surface is smooth, dry to the eye, and springs back immediately when pressed — no raw dough give at the centre.