Preheat oven to 350°F (175°C)
Brown the ground beef in a large skillet over medium-high heat drain any extra fat
Add the chopped onion, diced carrots and minced garlic and sauté until softened
Add the frozen mixed vegetables, beef broth, tomato paste, and Worcestershire sauce, season with salt and pepper
Simmer for 10-15 minutes until the mixture thickens
Transfer the beef mixture to a baking dish
Spread the mashed potatoes evenly over the beef mixture
Bake in the preheated oven at 350°F (175°C) for 25-30 minutes until the top is golden
Let cool for a few minutes before serving