Mashed Potato Casserole - cooking recipe

Ingredients

2-1/2 lbs white potatoes, peeled, boiled, and mashed
1/2 cup sour cream
4 oz cream cheese
1 Tbsp butter or oleo
1 tsp onion salt or 1 small onion, chopped
grated cheddar cheese

Preparation

Combine first 5 ingredients, beating until fluffy.
Sprinkle cheese on top.
Bake at 350 degrees for 20 minutes.
Serve.