Serves 3
1 pound (1- to 1 1/2-inch) broccoli florets (about 7 cups)
2 cloves garlic, thinly sliced
3 tablespoons olive oil
1/2 teaspoon kosher salt
1/4 teaspoon red pepper flakes
1/2 ounce finely grated Parmesan cheese (about 1/4 cup freshly grated or 2 tablespoons store-bought grated)
1 teaspoon finely grated lemon zest
1 tablespoon freshly squeezed lemon juice (1/2 medium lemon)
Arrange a rack in the middle of the oven. Place a rimmed baking sheet on the rack and heat the oven to 425°F.
Toss 1 pound broccoli florets, 2 thinly sliced garlic cloves, 3 tablespoons olive oil, 1/2 teaspoon kosher salt, and 1/4 teaspoon red pepper flakes together in a large bowl.
Remove the hot baking sheet from the oven. Transfer the broccoli to the baking sheet and arrange into a single layer cut-side down.
Return the baking sheet to the oven and roast until the broccoli is crisp-tender and browned, 15 to 17 minutes. Sprinkle with 1/2 ounce finely grated Parmesan cheese, 1 teaspoon finely grated lemon zest, and 1 tablespoon lemon juice. Toss to combine.