Start by preheating your oven to 375°F (190°C). This ensures that it’s at the right temperature when you’re ready to cook the meatloaf.
In a large mixing bowl, combine the ground beef, breadcrumbs, chopped onion, minced garlic, egg, milk, ketchup, Worcestershire sauce, salt, black pepper, and Italian seasoning.
Use your hands or a spoon to mix the ingredients until well incorporated, but be careful not to overwork the meat to avoid a dense meatloaf.
Transfer the meat mixture into a greased loaf pan and shape it into an even loaf. Spread a thin layer of ketchup on top of the meatloaf for a flavorful glaze that will caramelize as it cooks.
Place the pan in the oven and bake for about 45-55 minutes, or until the meatloaf reaches an internal temperature of 160°F (71°C).
While the meatloaf is baking, prepare the mashed potatoes. Place the peeled and chopped potatoes into a large pot and cover them with water.