Preheat the oven to 190°C (375°F). On a large baking tray, arrange the asparagus and garlic. Drizzle with 1 tbsp of olive oil and season generously with salt and pepper.
Pour over the balsamic vinegar and toss until the asparagus and garlic is well coated.
Move to the oven and roast for 10-12 minutes, or until the asparagus is tender yet still crisp and lightly browned at the tips. Serve.