1. Combine butter, zest, and thyme in small bowl. Brush asparagus with butter mixture, sprinkle with salt, and season with pepper to taste.

2. When grill is medium-hot, scrape grill grate clean with grill brush. Dip wad of paper towels in oil; holding wad with tongs, wipe cooking grate. Grill asparagus, turning once, until just tender and caramelized, 2 to 5 minutes per side (move asparagus as needed to ensure even cooking). Transfer asparagus to platter and serve.

Serves 4 to 6