Heat oven to 425°F. Cook chicken as directed on package.
Meanwhile, spray 12-inch pizza pan with nonstick cooking spray. In medium bowl, beat egg whites, Parmesan cheese, salt, rosemary and pepper with fork until well combined and slightly foamy. Add potatoes; mix well. Press potato mixture in pizza pan to form crust.
Cut cooked chicken into bite-sized pieces. Arrange chicken, tomatoes and olives over crust. Sprinkle with mozzarella cheese.
Bake at 425°F. for 15 to 18 minutes or until cheese is melted.