Scallion Pancakes with Black Vinegar Dipping Sauce

Name: Scallion Pancakes with Black Vinegar Dipping Sauce
Ingredients: 2 tablespoons black (Chinkiang) vinegar; 2 tablespoons oyster sauce; 2 tablespoons sweet soy sauce; 1 tablespoon chili oil; 1 teaspoon toasted sesame seeds; 2 cups all-purpose flour, plus more for dusting; ½ cup (or more) vegetable oil, plus more for brushing; 2 teaspoons kosher salt, divided; 6 scallions, very thinly sliced (about 1 cup), divided