If necessary, clean, trim, and cut the Brussels sprouts into halves before putting them in an oven-safe dish. Be sure to thoroughly dry them before cooking.
Olive oil should be added after the garlic, Parmesan cheese, salt, and pepper. Coat by tossing.
Roast uncovered in the oven for 20 to 25 minutes, or until the surface is crisp, golden, and caramelized and the inside is still soft. Serve with extra cheese, grated.