Adjust your oven rack to lowest position, and place a large rimmed baking sheet on rack, and heat oven to 500°F (260°C).
Cut each crown into 4 to 6 big wedges.
Place broccoli in a large bowl and drizzle with oil.
Toss well until evenly coated.
Sprinkle with salt and pepper along with garlic, and mix to combine.
Working quickly, remove the baking sheet from the oven. Carefully transfer broccoli and all oil and garlic to the baking sheet and spread into even layer, placing flat sides down.
Transfer to serving dish and serve immediately.