In a large mixing bowl, combine all-purpose flour with boiling water, stirring until a shaggy dough forms. Allow to cool for about 10 minutes, then knead for 5-7 minutes until smooth and elastic. Let rest covered with a damp cloth.

Divide the dough into equal portions. Roll one portion into a thin rectangle, brush with sesame oil, sprinkle with chopped scallions and a pinch of salt. Roll it up and coil into a snail shape, then flatten and roll into a pancake.

Heat a nonstick skillet over medium heat, add enough vegetable oil to coat the bottom. Fry each pancake for 2-4 minutes on one side until golden and crispy, then flip and cook for another 2-4 minutes, pressing down to ensure crispiness.

Transfer pancakes to a plate lined with paper towels to drain excess oil. Cut into wedges and serve with soy sauce or black vinegar.