In a large saucepan, cook the ground beef until no longer pink. Drain the excess grease. Add in onion and cook until soft. Stir in the taco seasoning.
Add in the corn, black beans and tomatoes, and mix until fully combined.
Spray two 9x13 foil pans with cooking spray. Spoon half of the rice into the bottom of each pan and press down evenly.
Spoon the meat mixture evenly over the rice. Top with the shredded cheese.
Cover with foil and label. Place in a large freezer bag, and freeze.
When ready to use, thaw overnight. Bake in the oven at 350°F for 45 minutes with the foil on. Remove the foil, and continue to cook until cheese is melted.