Position oven rack 6 inches from broiler. Preheat broiler to high.
Bring a few inches of water to a boil in a large pot fitted with a steamer basket. Steam broccoli until just tender, about 3 minutes.
Spread broccoli on a large rimmed baking sheet. Using the bottom of a Mason jar or sturdy glass, flatten each floret. Drizzle with oil and sprinkle with salt and pepper. Evenly distribute Parmesan over the florets. Broil until the broccoli is lightly browned and the cheese has melted, 3 to 4 minutes. Drizzle with balsamic glaze before serving.
