Trim tough ends from asparagus.
Zest and juice lemon.
Add oil, mustard, vinegar, lemon juice, 1/2 teaspoon zest, and thyme to a small mason jar. Shake to combine.
Drizzle asparagus with half the dressing and toss to coat.
Grill until asparagus turns bright green and tops begin to brown.
Remove from grill and drizzle with remaining dressing.
Season with salt and pepper to taste.
Serving Size 4 Servings