01 - Set oven to 425°F and prepare a baking sheet by lining it with parchment paper or lightly greasing it.
02 - Place the trimmed asparagus spears in a single layer on the prepared baking sheet.
03 - Drizzle olive oil evenly over the asparagus, then add minced garlic, kosher salt, black pepper, and red pepper flakes if using. Toss gently to coat all spears.
04 - Sprinkle grated Parmesan cheese evenly over the asparagus.
05 - Roast in the oven for 12 to 15 minutes until tender and cheese is golden and crisp.
06 - Remove from oven, transfer to a serving platter, and garnish with chopped parsley and extra Parmesan if desired. Serve immediately.