Wash and trim asparagus then toss in olive oil and season with salt and pepper to taste.
Heat grill to 400°F (200ºC).
Lay spears perpendicular to the grates so they don't fall through, and grill for 3–5 minutes per side (6–10 minutes total), turning with grill-safe tongs until tender-crisp, bright green and lightly charred.
Transfer to serving plates, and finish with a squeeze of fresh lemon and a sprinkle of freshly grated Parmesan (optional). Serve immediately.