Beefy Scalloped Potatoes

1 lb ground beef
1 small onion, chopped
1 (16 ounce) bag frozen green beans or mixed vegetables
1 (4 ounce) can mushrooms, drained (size is approx)
8-10 potatoes, peeled and sliced
1 (14 ounce) can cream of mushroom soup, Progresso brand (size is approx)
1-2 cup shredded cheese

Boil sliced potatoes until tender. Drain. Brown ground beef and drain. Spread in 9 X 13 glass dish. Sprinkle with chopped onion. Sprinkle half of shredded cheese over meat. Spread frozen green beans or mixed vegetables over meat and onion. Sprinkle mushrooms over vegetables. Spread cooked sliced potatoes over vegetables. Spread the rest of the shredded cheese and then pour mushroom soup over the entire casserole. (You could also make your own cheesy white sauce with butter, milk, and corn starch or GF flour and cheese such as Velveeta). Bake in 375-400 oven uncovered for about 30 minutes.