Preheat your oven to 375°F (190°C). In a large skillet, brown the ground beef over medium-high heat, breaking it apart with a spoon. Drain any excess grease. Add the chopped onion to the skillet with the browned meat and cook until the onion is softened and translucent, about 5-7 minutes.

Reduce the heat to medium-low. Stir in the condensed cream of mushroom soup, milk, garlic powder, onion powder, salt, and black pepper. If using, add the frozen mixed vegetables and Worcestershire sauce at this stage. Stir well to combine all ingredients and heat through, ensuring the mixture is smooth and creamy.

Pour the meat and sauce mixture into a 9x13 inch baking dish, spreading it evenly across the bottom. Sprinkle 1 cup of the shredded cheddar cheese over the meat mixture. Arrange the frozen tater tots in a single layer over the cheese, covering the entire surface of the casserole.

Bake for 30-35 minutes, or until the tater tots are golden brown and crispy, and the filling is bubbly. During the last 5-10 minutes of baking, sprinkle the remaining ½ cup of shredded cheddar cheese over the tater tots and continue baking until the cheese is melted and bubbly.

Once baked, remove the casserole from the oven and let it rest for 5-10 minutes before serving. This allows the casserole to set and makes it easier to serve. Serve hot, and get ready for a chorus of happy eaters! This casserole is a complete meal on its own, but it also pairs well with a simple side salad.