Cheating Scalloped Potatoes

In a bowl mix the cream of mushroom soup, milk, salt and pepper; set aside.
Grease a 13"x9"x2" oven proof dish.
Put 1/3 of the potatoes, 1/3 of the onions, 1/3 melted butter, 1/3 flour and a 1/3 of the soup mixture in the greased dish (take a minute to arrange them evenly).
Repeat with two more layers, ending with the soup mixture.
Bake uncovered at 350 degrees Fahrenheit for 1 and 1/2 hours or until potatoes are done and golden.