Refrigerator Mashed Potatoes
["5 lb. potatoes (9 large)", "2 (3 oz.) pkg. cream cheese", "1 c. sour cream", "2 tsp. onion salt", "1 tsp. salt", "1/4 tsp. pepper", "2 Tbsp. margarine"]
["Cook peeled potatoes in boiling salted water until tender. Drain.", "Mash until smooth (no lumps).", "Add remaining ingredients and beat until light and fluffy.", "Cool."]
["potatoes", "cream cheese", "sour cream", "onion salt", "salt", "pepper", "margarine"]