Heat the olive oil in a large skillet over medium heat. Add the pancetta and cook, stirring often, until rendered and crisp, about 6 minutes. Remove with a slotted spoon to a paper towel-lined plate to drain.
Increase the heat to medium high and add the Brussels sprouts, 1/2 teaspoon salt and a few grinds of pepper to the pan. Cook, stirring often, until bright green and slightly wilted, 2 to 3 minutes. Remove from the heat and drizzle in the vinegar; toss well to coat. Transfer to a bowl and top with the pancetta.