Boil potatoes in salted water until tender, about 20 minutes. Drain and mash with milk and butter. Season with salt and pepper to taste.
Ground Beef & Gravy:
Brown the ground beef in a skillet, then drain excess fat.
Add onion and garlic; cook until translucent, about 5 minutes.
Sprinkle flour over the mixture and cook for 2 minutes, stirring constantly.
Slowly add beef broth and Worcestershire sauce, stirring until smooth. Simmer for 5 minutes until thickened.
Add peas and carrots if using, and season with salt and pepper.
Serve:
Spoon mashed potatoes onto plates and top with the beef and gravy mixture. Serve hot and enjoy!
