Preheat the oven to 475 degrees F (245 degrees C).
Combine olive oil and garlic in a small bowl.
Cut broccoli into florets with 2 to 3 inches of stem and spread on a rimmed baking sheet. Pour garlic oil over broccoli and toss to coat. Season with salt and pepper.
Roast in the preheated oven, turning once, until broccoli is tender and charred at edges, 7 to 9 minutes. Transfer to a serving dish and sprinkle with vinegar.