2 oz. goat cheese or feta cheese, crumbled (optional)
Fresh thyme sprigs (optional)
Preheat grill to medium-high.
To make dressing, whisk together 2 1/2 tbsp. oil, vinegar, salt and pepper in small bowl. Whisk in thyme and set aside.
Trim onions to same length as asparagus spears. Combine asparagus and onions in medium bowl. Add remaining 1 tbsp. oil and toss to coat. Place vegetables on grill rack and grill, turning often, about 6 minutes for onions and about 4 minutes for asparagus, until lightly browned, crisp and tender.
Transfer vegetables to a serving platter. Whisk dressing again and drizzle over vegetables; toss to coat. Top with goat cheese and garnish with thyme sprigs, if you wish. Serve hot or at room temperature.