Preheat your oven to 400°F.
In a large bowl, combine the halved Brussels sprouts, olive oil, minced garlic, salt, and black pepper. Toss until the Brussels sprouts are well coated.
Spread the Brussels sprouts in a single layer on a baking sheet.
Roast in the preheated oven for 20-25 minutes, or until they are golden brown and crispy on the edges, stirring halfway through for even cooking.
Remove from the oven and sprinkle the grated Parmesan cheese over the hot Brussels sprouts. Return to the oven for an additional 5 minutes, until the cheese is melted and slightly golden.
Drizzle with balsamic vinegar if desired before serving.