Layer sliced potatoes and onion in 9x12 baking dish. Sprinkle with salt, pepper, and parsley.Put butter in small cubes over potatoes.Place cheese cubes over mixture.Sprinkle with flour.Slowly pour milk over potatoes and top with bread crumbs.Bake at 425 for 5 min. or until milk bubbles. Then bake at 375 for 45-60 min. uncovered.
Tip: Put a baking sheet on shelf under dish to catch any overflow.