Classic Scalloped Potatoes Recipe

Who doesn't love scalloped potatoes? Yet, when it's time to make them, who doesn't cast around for the "Perfect" Recipe for this simple dish? We love this particular version. First, because the potatoes bake in an onion-scented white sauce, rather than plain milk; and second, because it makes a large amount. When you're serving a big family dinner, you don't want to run out of potatoes