I'm a meat and potatoes girl and this is one of my favorite side dishes. It's not actually scalloped potatoes and it's not Au Gratin potatoes. I call it Potato Casserole and it's delicious.
Cheesy Potato Casserole
2 cups mashed potatoes (you can use leftover made with milk or cream and butter)
1/2 cup sour cream
1 onion, sliced thin
8 tablespoons (1 stick) butter
2 cups grated Cheddar Cheese
4 medium whole potatoes, cooked and sliced 1/4 inch thick
1/2 teaspoon garlic powder
1/2 teaspoon salt
1/2 teaspoon pepper
Preheat oven to 350 degrees. Spread mashed potatoes evenly on bottom of casserole dish. Layer sour cream evenly over top. Sprinkle with a little garlic powder, salt and pepper between each layer. Saute onion in butter and then evenly layer the slices of onion and the butter on top of the sour cream. Next, layer with 1/2 cup of the cheddar cheese.
Add a layer of your cooked sliced potatoes over the cheese until you have completely covered the top with sliced potatoes. Next add the remaining cheese. Bake for 25-30 minutes. Remove from oven and for a real treat crumble bacon over top.