In a large skillet over medium heat, add the lean ground beef. Cook until browned, breaking it up with a spatula as it cooks, about 5-7 minutes.
Once the beef is browned, add the chopped onion and minced garlic to the skillet. Sauté for an additional 3-4 minutes until the onion becomes translucent and fragrant.
Stir in the Worcestershire sauce, Italian seasoning, salt, and pepper. Mix well to combine and let it cook for another minute.
In a mixing bowl, combine the sour cream, condensed cream of mushroom soup, and drained corn. Stir until smooth and well combined.
Add the beef mixture to the creamy mixture, along with 1 cup of the shredded cheddar cheese. Stir until everything is evenly distributed.
Spread the beef and creamy mixture evenly in a 9x13-inch baking dish. Top it with the frozen tater tots, arranging them in a single layer.
Preheat your oven to 375°F (190°C). Bake the casserole for 30-35 minutes, or until the tater tots are golden brown and crispy.
Remove the casserole from the oven, sprinkle the remaining 1 cup of shredded cheddar cheese on top, and return it to the oven for an additional 5-10 minutes, or until the cheese is melted and bubbly.
Once baked, allow the casserole to cool for a few minutes. Serve warm, garnished with chopped scallions if desired.
