01 - Set the oven to 425°F and line a baking sheet with parchment paper.
02 - In a large bowl, combine broccoli florets with olive oil, minced garlic, kosher salt, black pepper, and crushed red pepper flakes if using. Toss to coat thoroughly.
03 - Spread the broccoli evenly in a single layer across the prepared baking sheet.
04 - Bake for 18 to 20 minutes, stirring once halfway through, until the broccoli is crisp-tender and lightly browned on the edges.
05 - Remove from oven and immediately toss with lemon juice and zest.
06 - Transfer to a serving dish and garnish with fresh parsley and grated Parmesan if desired. Serve warm.