Step 1

Arrange one rack in the middle of the oven and one rack in the highest position, then heat to 450°F. Place a rimmed baking sheet in the oven while it's heating.

Step 2

Combine the broccoli, olive oil, salt, and a few grinds of pepper in a large bowl and toss to coat. Carefully remove the hot baking sheet from the oven, add the broccoli, and spread it into an even layer. Roast on the middle rack until the broccoli is tender and beginning to brown at the edges, 15 to 18 minutes.

Step 3

Remove from the oven. Switch the oven to broil. Scatter the Parmesan evenly over the broccoli. Return to the oven and broil on the upper rack until the cheese melts, 1 to 2 minutes. Squeeze the juice from one lemon half over the broccoli and toss to combine. Cut the other lemon half into wedges and serve alongside the broccoli.