Preheat the oven to 400° F
Place the brussels sprouts onto a lined sheet pan, making sure to include all of the loose leaves, which get crispy when they’re roasted.
Cut the pancetta into ½-inch dice and add it to the pan
Add the olive oil, a strong pinch of salt, and a grind or two of black pepper. Toss with your hands
Spread out the brussels sprouts in a single layer
Roast for 20 - 30 minutes, or until they’re tender, nicely browned, and the pancetta has finished cooking. (Toss once about half-way through roasting)
Remove from the oven, drizzle immediately with the balsamic vinegar, and toss again.
Taste for seasonings and serve hot.