Roasting broccoli is a wonderful change from steaming or stir-frying, bringing out a sweetness and complexity you might not have known was there. A simple finish of bright lemon and salty cheese adds a burst of freshness and flavor.
Preheat oven to 425°. Line a 15x10x1-inch baking pan with foil. Add broccoli and olive oil to the pan; toss to coat, arranging larger pieces near the edges of pan. Season with salt and pepper. Roast 15 minutes. Turn and roast until broccoli is just tender and nicely charred, about 10 minutes more.
Zest the whole lemon over the broccoli, then squeeze juice from half of the lemon over the broccoli. Sprinkle with cheese.
Pecorino Romano is a firm, sharp-tasting sheep's milk cheese. It's similar to Parmesan, which makes a fine substitute.