Preheat oven to 375 degrees
Cook the ground beef and onions in a skillet over medium heat until ground beef is browned and onions are translucent. Drain as necessary.
Spray a 9 X 13 pan with cooking spray.
Place meat and onion mixture in the bottom of the pan. Spread vegetables evenly over the meat mixture. Spread the cream of mushroom soup evenly over the vegetables. Sprinkle with salt and pepper.
If adding cheddar cheese, sprinkle over soup layer.
Place tater tots evenly on top of the mixture in straight rows. Do not place them over the top of each other so they will cook properly.
Bake for 45 minutes, uncovered, or until the vegetables are soft when pierced with a fork and the tater tots are crispy and golden brown. Also look for dish to bubble around the tots. If needed, place dish back into the oven for 10 to 15 minutes, then check again. Repeat as necessary until done. Cool slightly and enjoy!