High smoke point oil for the pan, such as vegetable, canola, or peanut oil
Mix 2 1/2 cups flour with 1 cup water until it forms a smooth dough. Knead by doubling the dough over and pressing it down repeatedly, until the dough is even smooth and very elastic. Coat this ball of dough lightly in oil and put it back in the bowl. Cover the bowl with a damp cloth and let the dough rest for about 30 minutes. Finely chop the bunch of scallions while you wait.
Cut the dough into 4 equal parts. Lightly oil the back of a large metal baking sheet (or a marble countertop). Roll out one part of the dough on the back of the baking sheet. Roll until it is a thin (kind of) rectangle.
Lightly brush the top of the dough with oil, then sprinkle it evenly with chopped scallions and kosher salt. Starting from the long end, roll the dough up tightly, creating one long snake of rolled-up dough.
Cut the dough snake in two equal parts. Take one of these halves and coil into a round dough bundle (if it looks like a turd, you're doing it right). Let it rest for at least 15 minutes or longer, while you repeat this process with the rest of the dough.
Pat a coiled dough bundle into a flat, smooth, round pancake. You can do this with a rolling pin or with your hands.
Next, heat a 10-inch heavy skillet or sauté pan over medium-high heat, and oil it with a drizzle of oil. When the oil shimmers, pick up the pancake dough and lay it gently in the pan. It should sizzle, but not burn. Cook for 2 minutes on one side, flip and cook until golden brown.