Make the hot-water dough: In a large bowl, mix flour and 1/4 teaspoon salt. Pour in the hot water and stir with chopsticks, a fork, or a spoon until shaggy clumps form.
When cool enough to handle, knead on a clean counter for about 5 minutes until smooth. Cover with a damp towel and let rest for 30 minutes.
Prep scallions: Finely chop scallions. Mix dipping sauce ingredients (soy sauce, rice vinegar, sesame oil, sugar, and optional chili oil) and set aside.
Divide and roll: Cut dough into 4 equal pieces. Roll one piece into a thin circle about 8 inches wide.
Layer: Brush the surface with about 1 teaspoon toasted sesame oil. Sprinkle with a pinch of salt and about 1/4 cup chopped scallions. Roll tightly into a log, then coil into a spiral. Flatten gently with your hand.
Roll the spiral into a 6-inch circle. Repeat with remaining dough pieces.
Pan-fry: Heat 1–2 tablespoons neutral oil in a skillet over medium heat. Cook each pancake 3–4 minutes per side, until golden brown and crisp, adding more oil between batches as needed.
Transfer to a cutting board, slice into wedges, and serve hot with the dipping sauce.