Make the main dough: Slowly stir the hot water to the flour. Wait until cooled down and knead until it forms a smooth dough. Or knead the dough with a stand mixer for 5-7 minutes with low speed.
Rest the dough: Cover with plastic wrapper or a wet cloth and rest for at least 30 minutes. So the gluten can be well rested and we can easily roll the pancake out.
Make the oil-flour mixture: heat oil over medium fire and fry green onions until browned. Discard the green onion and keep the oil. Pour flour into a small bowl and stir in the hot oil slowly.
Roll out the dough: Cut the dough into 4 equal portions and roll one portion out to a large rectangle wrapper. Sprinkle salt and top with a layer of oil-flour mixture and then another layer of chopped scallion.
Roll-up the dough: Starting from the long end, roll the dough up like folding a hand fan. Slightly stretch and roll one side up to the middle and then the other side to the middle too. Overlay the two ends. Cover the dough and rest for 15 minutes or so. Repeat the process and finish all of the remaining portions. The former twos with more layers are assembled with the hand folding fan methods, while the two in the second line is made with simply roll up method.
Roll each portion to a large pancake (around 5 inches in diameter). If you plan to cook the pancakes later, package each of them with an air-tight bag and freeze up for 1 week.
Frying the pancakes: add around 3 tablespoons of oil in a pan and fry the pancakes until golden brown on one side (takes 3-4 minutes over medium fire), turn over the fry the another side for 3 minutes too. After turning over, slightly press the center of the pancake so they can be fried evenly.