In a large mixing bowl, combine 2 cups of all-purpose flour and gradually pour in boiling water while stirring with a wooden spoon. Continue mixing until it comes together in a shaggy dough. Let it cool for about 10 minutes, then knead for 5-7 minutes until the dough is smooth and elastic. Cover the dough with a damp cloth and let it rest for 20 minutes to relax.

Once the dough has rested, divide it into equal portions, each roughly the size of a golf ball. Roll one portion into a thin rectangle on a lightly floured surface, about ¼ inch thick. Brush the surface generously with sesame oil, then sprinkle with chopped scallions and a pinch of salt. Roll the rectangle into a tight cylinder, then coil it into a snail shape and flatten it gently with your palm.

With a rolling pin, carefully roll out the coiled dough again into a flat disc approximately 6-8 inches in diameter. Aim for a thickness of about 1/8 inch for the best texture in your Crispy Chinese Scallion Pancakes. Repeat the shaping process with the remaining dough portions, placing each rolled pancake on a lightly floured surface while you prepare to cook them.

Heat a nonstick skillet over medium heat and add enough vegetable oil to lightly coat the bottom. Once the oil is shimmering, gently place one pancake in the skillet and fry for about 2-4 minutes on each side, or until golden brown and crispy. Press down lightly with a spatula to ensure even cooking and blistering on the surface. Remove the pancake and set it aside on a paper towel-lined plate to absorb excess oil.

Continue cooking the remaining pancakes, adding a bit more oil to the skillet as needed. Once all your Crispy Chinese Scallion Pancakes are cooked and crispy, slice them into wedges. Serve them warm with a small bowl of soy sauce or black vinegar for dipping.