I'm going to start this one off by saying that my mother is an amazing cook. We've always eaten really delicious food, and I like to think that I've absorbed some lessons through the years, although most of my attempts come nowhere near hers. However, there are a few recipes I've learned and perfected, and in the case of scallion pancakes, I think mine are better now. (Don't tell my mom I said that.)
To make 16 5-6" pancakes, combine 3 cups of all purpose flour and a teaspoon of salt. Pour in 1 1/4 to 1 1/2 cups of boiling water; stir with chopsticks (or a fork) until mostly combined. You'll have a fairly dry, shaggy looking mass. Turn it out onto a clean countertop and knead until you have a smooth, pliable dough. You may need to add a tablespoon or more of water, but don't add much more than that--the dough should not be sticky at all. Cover with a towel and set aside while you prepare the filling.
For the oil, combine 2 tablespoons of olive oil and 2 teaspoons of sesame oil. Finely chop approximately 4 scallions, greens and whites--you should have about 3/4 of a cup total. If you have any available, you can add some finely chopped garlic chives as well.
Divide dough into two parts, and keep the one you're not working with covered with a towel. Roll the half into a rope and cut into 8 equal portions. Working with one at a time, roll out into a circle; try to roll it out thinly (less than 1/8" thick). Brush all over with a thin layer of oil, and sprinkle with a bit of salt.
Scatter some scallions evenly across your dough circle. I use about a teaspoon, but obviously you can increase or decrease depending on how scallion-y you like your pancakes. Roll your pancake up snugly into a sausage, like you would a cinnamon roll. Don't worry too much about pinching the seams shut or anything.
Form your sausage into a coil and tuck the end under into the center. These last two steps are what give the pancakes their flakiness. Flatten down into a round patty. You should end up with something that looks like this:
Dust both sides with flour and roll out again into a 5-6" round circle. Don't worry if some of the filling is forced out--you can just poke it back in. Similary, don't worry if you can't get them completely round; they'll still taste good, I promise.
As you roll them out, stack them on a plate with a layer of parchment or plastic wrap between each one. If you aren't planning on eating all 16 right away (tempting, but I don't recommend it if you don't have a large group of people. Trust me.), then once you have them rolled out, pack them into a freezer bag and store in the freezer. They'll keep for quite a while and it's convenient to have a stash on hand for emergencies.
When you're ready to cook them, heat a splash of vegetable oil in a skillet over medium-high heat. When hot, put a pancake in; it should sizzle a bit, but keep the heat controlled so it doesn't brown too fast. When there are browned spots and the surface looks dry, flip the pancake and press down with your spatula. (For reasons I can't explain, this helps to encourage the pancake to puff up a bit, forming flaky layers). Cook until the second side has browned spots. Remove from the heat, cut into quarters, and serve plain or with dipping sauce (in this case, 2 tablespoons of soy sauce, a dollop of sambal oelek, a few drops of sesame oil, and half a clove of garlic, smashed). Repeat as necessary!