In a large saucepan, cook the potatoes, covered, in a small amount of lightly salted boiling water for 11 minutes. Add asparagus. Cook, covered, about 4 minutes more or until asparagus is crisp-tender and potatoes are tender; drain. Transfer to a serving platter.
Meanwhile, in a small bowl combine salad dressing and lemon peel. Drizzle salad dressing mixture over potatoes and asparagus. Arrange prosciutto beside vegetables. If desired, top with Parmesan cheese ribbons. Serve warm. Makes 8 servings.