In a large skillet over medium heat, cook ground beef and onion until beef is browned and onion is soft. Drain any excess grease.
Stir in the corn, cream of mushroom soup, cooked egg noodles, and milk.
Season with salt and pepper to taste.
Simmer for 5–10 minutes, stirring occasionally, until everything is heated through.
Serve hot, topped with shredded cheese if desired.