Place one-fourth of the asparagus spears in a steamer basket. Place in a large skillet with one inch boiling water. Cover and steam for 4 minutes. Remove asparagus from steamer basket. Repeat with remaining asparagus, steaming 1/4 at a time.

Wrap one cheese slice and then a half slice of prosciutto around each asparagus spear. Arrange wrapped asparagus in two 3-quart rectangular baking dishes, layering as necessary. For dressing, in a screw-top jar combine olive oil, balsamic vinegar, and pepper; shake well to mix. Drizzle half of the dressing over each dish. Cover and chill up to 24 hours.

To serve, arrange on a serving platter. If desired, wrap each roll with a chive and tie. Makes 50 servings.