In a large bowl, combine the all-purpose flour, instant yeast, and sugar, and mix well. Gradually pour in the warm water while stirring until no dry flour remains and the mixture forms a shaggy dough.

Add the chopped scallions and knead the dough by hand until it comes together. Transfer to a work surface and knead until smooth. The dough should be soft — this softness is key to achieving flaky layers.

Return the dough to the bowl, cover, and let it rest for 10 minutes. This allows the gluten to relax, making the dough easier to roll without tearing.

In a small bowl, mix the flour and pepper salt until combined. Heat the oil until hot and lightly smoking, then immediately pour it over the flour mixture.

Stir quickly with chopsticks or a spoon until a thin, pourable oil paste forms. The paste should not be too thick, or it will be difficult to spread evenly.

Lightly dust the work surface with dry flour. Roll the rested dough into a large, even sheet about 0.3 cm thick.

Pour the oil paste over the surface and spread it evenly with a brush or spoon. Starting from one end, roll the dough tightly into a long log, pinching the seam to seal so the oil paste doesn't leak during cooking.

Gently roll the log to lengthen it slightly, then cut it evenly into 6 portions. Take one portion, tuck both ends inward to seal, and roll it into a round.

Lightly brush the surface with water, coat evenly with white sesame seeds, then press flat with your palm. Use a rolling pin to shape it into an oval. Flip and roll once more to ensure even thickness.

Repeat with the remaining dough portions, keeping them covered to prevent drying.

Heat a frying pan over medium-low heat and brush with a thin layer of oil. Place the flatbreads into the pan, brush the tops lightly with oil, and cover with a lid.

Cook for 3–4 minutes until the bottom is golden and set. Flip, cover again, and cook for another 3–4 minutes until both sides are golden and crisp.

Press gently on the flatbread — if it springs back quickly, it's ready to serve.