Preheat the oven to 375°F (190°C).
In a large skillet, cook the ground beef, onion, and garlic over medium heat until the beef is browned and the onion is softened.
Add the frozen mixed vegetables, beef broth, tomato paste, Worcestershire sauce, salt, and pepper. Stir well and bring to a simmer. Cook for 5 minutes.
Transfer the beef mixture to a 9x13-inch baking dish and spread the mashed potatoes on top. Sprinkle with shredded cheddar cheese.
Bake for 25-30 minutes, or until the cheese is melted and bubbly.
Serve hot and enjoy!