On a large sheet pan, toss the Brussels sprouts together with the olive oil, salt, and pepper.
Roast for 25-30 minutes, or until lightly browned and tender.
Meanwhile, heat a medium skillet on medium heat. Add the diced pancetta and cook until crispy, about 5 minutes. Drain on a paper towel lined plate. With a small amount of grease remaining in the pan, add the shallots and garlic and cook, sauteing occasionally until softened, about 3 minutes. Add the pancetta back to the pan, turn off the heat, and set aside.
When the brussels are done cooking, toss them with the pancetta-shallot mixture, balsamic vinegar, and maple. syrup Serve immediately.
Notes
The pancetta, shallots, and garlic can be cooked the day before and stored in an airtight container in the refrigerator. When ready to serve, add the pancetta mixture to the sheet pan for the last 5 minutes the Brussels are cooking to reheat.