Potato Casserole

Potato Casserole
2 c mashed potatoes (I used instant)
1 c [light] sour cream
garlic salt and pepper, to taste
3 large (or 4 medium) potatoes, sliced and cooked*
1 onion, diced thin
1/4 c butter
1 1/2 c Cheddar cheese
6 slices [turkey] bacon, cooked (opt)

1. Preheat oven to 350*.
2. Spread mashed potatoes evenly on the bottom of a 9x13 pan; spread sour cream over potatoes and sprinkle with garlic salt and pepper.
3. Layer potatoes next; saute onions in butter and pour over potatoes. Top with cheese.
4. Bake for 25-30 minutes. Remove from oven and crumble bacon on top.
*Peel and slice the potatoes thin, then boil then for about a half hour until soft.