Mexican Casserole with hamburger

1 lb extra lean ground beef 1 cup onion , chopped 1 (14 ounce) can diced tomatoes , drained 1 1/2 cups frozen corn 1 (540 ml) can black beans , drained and[...]

1 1/2 lbs ground deer meat (browned and drained) or 1 1/2 lbs hamburger meat (browned and drained) 1 (8 ounce) can cream of mushroom soup 1 (8 ounce) can[...]