Preheat oven to 450°F.
Clean Brussel sprouts in water and trim tough ends and cut in half.
In a small bowl, whisk together oil, half the balsamic vinegar, garlic, salt, and pepper.
Spread the sprouts out evenly over a foil-lined baking sheet. Drizzle the oil mixture over the sprouts, and toss to evenly coat. Spread back into an even layer.
Roast for 20-25 minutes or until the sprouts tender with a crisp outside. Remove from oven.