1. Stir together first 8 ingredients. Cover citrus sauce, and chill 1 hour.
2. Snap off and discard tough ends of asparagus; remove scales with a vegetable peeler, if desired.
3. Fill an asparagus steamer with 2 inches water, and bring to a boil over medium-high heat. Place asparagus, cut ends down, in steamer basket; place basket in steamer, cover, and steam 6 to 7 minutes or just until asparagus spears are tender.
4. Plunge asparagus into ice water to stop the cooking process; drain.
5. Arrange asparagus spears on serving platter. Garnish citrus sauce, if desired, and serve with asparagus.