1 (8 oz.) pkg. Philadelphia cream cheese
4 c. hot mashed potatoes (may be made from instant)
1 egg, beaten
1/4 c. onion, chopped
1/4 c. pimento, chopped (optional)

Preheat oven to 350 degrees. Spray 2 quart casserole with cooking spray. Mix all ingredients together. Pour into dish. Bake 45 minutes.