Ham Noodle Casserole

1 lb cubed ham
2 cans cream of mushroom soup
2 lbs sharp cheddar cheese
1 tub sour cream
1 diced onion, sauteed in butter
1 large bag wide egg noodles

Mix all in large bowl and spread in casserole dish. Top with crushed corn flakes and bake at 350 for 25 minutes or until heated.