Preheat the oven: Set to 425°F (220°C). Line a sheet pan with parchment for easy cleanup.
Prep the asparagus: Snap or trim off the woody ends (about 1 to 2 inches). Pat dry so oil and cheese stick well.
Season: Toss asparagus on the pan with olive oil, garlic, salt, pepper, and lemon zest. Spread into a single layer.
Bake first: Roast for 8 minutes to start tenderizing the stalks.
Add the cheese: Pull the pan out, sprinkle mozzarella and Parmesan evenly. Add red pepper flakes or paprika if you like heat or smokiness.
Finish baking: Return to the oven for 4 to 6 minutes until cheese melts and bubbles. For extra golden tops, broil 1 minute.
Brighten and serve: Squeeze on fresh lemon juice. Serve hot while the cheese is melty.
