Preheat the oven to 500 F.

Pat the wings very dry with a paper towel. Heat a large (14-inch) cast iron skillet or two smaller cast iron skillets over high heat until smoking hot. Add just enough of the oil to coat the bottom of the pan. Using tongs, set the wings in the pan in a single layer with the meatiest side down. This will help render the fat. Cook the wings for 2 minutes, then transfer the skillet to the oven for 5 minutes. Carefully remove the skillet from the oven and, using tongs, flip the wings over. Continue baking until the wings are cooked through and the juices run clear, another 10 minutes.

Combine the sriracha, vinegar, soy sauce, sugar, and garlic in a small saucepan. Bring to a boil over high heat, then cut the heat down to medium-low and simmer for 5 minutes. Pour the sauce into a large bowl and toss in 1 tablespoon of the scallions.

Carefully remove the skillet from the oven and, using tongs, transfer the wings to the bowl and toss with the sauce. Transfer to a platter and garnish with the remaining 3 tablespoons scallions.