1. In a large skillet, bring 2 cups of salted water to a boil. Add the asparagus and cook until it is crisp-tender, about 2 minutes. Drain and plunge the asparagus into a bowl of ice water to cool it quickly. When the asparagus is cool, remove it from the ice water and set it aside.
2. Place the remaining ingredients in a food processor and puree.
3. Toss the asparagus with the lemon dressing. Store in the refrigerator (up to 2 days) until ready to serve.