Preheat the oven to 375°F. In a large skillet over medium-high heat, cook the ground beef with the green bell pepper and onion until the beef is cooked. Drain excess fat if needed.
Add the minced garlic and Worcestershire sauce, and season with salt, pepper, and Italian seasoning.
Stir in the condensed cream of mushroom soup and drained corn until well mixed. Transfer the mixture into a baking dish. Sprinkle 1 cup of cheddar cheese over the beef mixture.
Arrange the frozen Tater Tots evenly on top. Bake for about 35 minutes.
Top the casserole with the remaining shredded cheese and bake for 10 minutes longer until the Tater Tots are golden and the cheese is bubbly. Garnish with chopped green onions.