Preheat oven to 400°F. Place the brussels sprouts on a baking sheet, including some of the loose leaves, which get crispy when they’re roasted. Cut the pancetta into 1/2-inch dice and add to the pan. Add the olive oil, the 1 1/2 tsp. salt and the 1/2 tsp. pepper and toss with your hands. Spread out the mixture in a single layer.

Roast the brussels sprouts until they’re tender and nicely browned and the pancetta is cooked, 20 to 30 minutes, tossing once during roasting. Remove from the oven, drizzle immediately with the balsamic vinegar and toss again. Taste and adjust the seasoning with salt and pepper. Serve hot. Serves 6.

Note: You can buy aged balsamic vinegar that’s syrupy—and very expensive—or you can boil good balsamic vinegar until reduced to half its volume and it will become syrupy as well.