Add 500g flour, 10g sugar, and 3g yeast to a bowl and mix well. Gradually pour in 270ml water while stirring with chopsticks until no dry flour remains. Knead by hand for 5–8 minutes until the dough is smooth, elastic, and non-sticky. No need to ferment—move on directly.

Lightly dust the work surface. Roll the dough into a large rectangle about 0.3–0.5cm thick. Spread the red bean paste evenly over half of the dough. Fold the uncovered half over the filling, press the edges to seal, then gently roll again to even out the layers.

Fold the dough like a blanket into thirds, pressing lightly each time to remove air. Cut into pieces about 5–6cm wide, keeping the edges neat.

Stack two pieces together with the cut sides facing up. Press a chopstick firmly down the center. Hold both ends, twist gently in one direction, then roll into a spiral. Tuck the end underneath to secure. Repeat with all pieces.

Line the steamer with a damp cloth. Arrange the rolls with 2–3cm space between them. Cover and let proof in a warm place until noticeably puffy and springy to the touch (about 20–30 minutes at room temperature).

Bring the water to a full boil. Place the steamer over the pot and steam over medium heat for 15 minutes. Turn off the heat and let rest for 2–3 minutes before opening the lid. Serve warm.