Mexican Casserole - With greens

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 lb ground chuck 1 (1 1/4 ounce) package taco seasoning mix 1 (14 1/2 ounce) can whole tomatoes , chopped and un-drained 1 (8 1/2 ounce) can whole kernel[...]

1 lb ground beef 1 (1 1/4 ounce) package taco seasoning 1 (5 7/8 ounce) package taco shells, crushed 1 (8 ounce) package shredded taco cheese 1 Brown ground[...]