In a large bowl, combine 500g flour, 5g yeast, and 10g sugar. Mix evenly.
Gradually add 270g warm water while stirring with chopsticks until the mixture forms shaggy flakes and no dry flour remains.
Knead into a dough. If flour sticks to the bowl, use the dough to wipe the sides clean. Transfer to a kneading surface and knead thoroughly until the dough becomes smooth, elastic, non-sticky, and slightly glossy.
Note: The water should feel warm but not hot. If too hot, it may deactivate the leavening and prevent proper rising.