Do Ahead Mashed Potatoes - cooking recipe

Ingredients

5 lb. potatoes, peeled and quartered
2 tsp. onion salt
1 egg
1 c. sour cream
1/2 tsp. pepper
2 Tbsp. oleo or butter

Preparation

Cook potatoes, mash or whip until smooth.
Add the rest of ingredients except butter.
Put in a greased casserole.
Dot with butter.
Cook at 350\u00b0 for 40 minutes or until heated through.
I find this recipe great for Thanksgiving or Christmas.
Can be made ahead a couple of days or frozen.