Heat Activated: Preheat your oven to a robust 425°F (220°C). Place a large, rimmed baking sheet inside the oven while it preheats. This ensures the pan is hot when the asparagus hits it, promoting better browning.
Prepare the Spears: Thoroughly rinse the asparagus under cool water. Snap off the tough, woody ends at the base of the spears. Pat the asparagus completely dry using a clean kitchen towel or paper towels. Dryness is crucial for achieving a nice roast rather than a steam.
Infuse with Flavor: In a large bowl, toss the dried asparagus with the olive oil, minced garlic, coarse sea salt, freshly cracked black pepper, and red pepper flakes (if using). Ensure each spear is well coated with the aromatic mixture.
First Stage Roast: Carefully remove the heated baking sheet from the oven. Spread the seasoned asparagus in a single, even layer across the hot surface. Avoid overcrowding the pan, as this can lead to steaming instead of roasting. Return the baking sheet to the oven and roast for 7 minutes.
Citrus Zest: While the asparagus is roasting, use a microplane or fine grater to zest the entire lemon. Set the zest aside. Cut the lemon in half.
Final Crisp: After the initial 7 minutes, remove the baking sheet from the oven. If desired, sprinkle the grated Parmesan cheese evenly over the asparagus. Return the pan to the oven for another 5-8 minutes, or until the asparagus is tender-crisp and lightly browned. Watch closely to prevent burning.
Lemon Finish: Transfer the roasted asparagus to a serving platter. Immediately sprinkle the reserved lemon zest over the top. Squeeze the juice from one half of the lemon over the asparagus. Toss gently to distribute the flavors. Taste and add more lemon juice or salt as needed. Serve immediately with the remaining lemon half cut into wedges.
