Cheesy Potato Casserole

2 lbs. potatoes, peeled if desired 

1 small onion, chopped

1/4 t. pepper

1 can cream of chicken soup

3 T. margarine, or butter, melted

1/4 c. margarine or butter, melted

1 t. salt

8 oz. sour cream

2 c. (8 oz) shredded cheddar cheese

1 1/2 c. herb seasoned stuffing mix

Cook potatoes in boiling water until tender. Drain. Cool. Cut into 1/4" strips. Set aside. Combine 1/4 c. melted margarine, onion, salt, pepper, sour cream and soup. Add potatoes and cheese. Spoon into sprayed 9x13 dish. Combine 3 T. melted margarine and stuffing mix. Sprinkle over casserole. Bake, uncovered, at 350 for 25 minutes until heated thoroughly.