Snap off tough ends of asparagus; remove scales with a knife or vegetable peeler, if desired. Steam asparagus, covered, 4 minutes or until crisp-tender. Rinse under cold water; drain well.
Arrange 1 cup greens on 4 plates; top each serving with 5 asparagus spears. Combine vinegar and next 5 ingredients (vinegar through garlic) in a small bowl; stir well with a whisk. Drizzle 1 tablespoon vinaigrette over each serving; top each with 1 tablespoon croutons. Sprinkle with parsley, if desired.