1. Freeze cheese 45 minutes to 1 hour. Meanwhile, cook potatoes in boiling water to cover 25 to 30 minutes or until tender; drain and cool completely.
2. Peel potatoes, and cut into 1-inch cubes. Grate frozen cheese, using large holes of a box grater.
3. Preheat oven to 325°. Whisk together mayonnaise and half-and-half in a large bowl. Stir in onion, olives, potatoes, and cheese until blended. Add salt and pepper to taste. Spoon into a 13- x 9-inch baking dish coated with cooking spray. Top with bacon pieces.
4. Bake at 325° for 55 minutes. Increase oven temperature to broil, and broil 5 minutes or until bacon is crisp. Let stand 5 minutes.