Wash and dry the peppers. Set aside. Heat a large cast iron skillet over high heat.

While the skillet is heating, whisk together the vinegar, mayonnaise, sugar, mustard, salt, and pepper in a small bowl. Set aside.

When the pan is hot, place the peppers in the pan and char on all sides (about 5 minutes.)

While the peppers are charring, toss together the coleslaw mix and the chopped green onions. When the peppers are charred, very carefully remove them from the pan, remove the tops and seeds, and slice (they will be hot and will probably steam when you cut them open. Please don't sue us if you burn yourself.) Toss the charred peppers in with the coleslaw mixture, then toss with the dressing. Allow to stand for at least 10 minutes. Season with additional salt and pepper to taste and serve as a side dish or as an incredible topping for grilled sausages, hot dogs, burgers, or tacos.