Preheat your oven to 350°F (175°C).
In a mixing bowl, combine ground beef, breadcrumbs, egg, milk, onion, garlic, Worcestershire sauce, salt, and pepper. Mix well.
Press the meatloaf mixture into a baking dish, forming an even layer.
Bake in the preheated oven for 45 minutes.
While the meatloaf is baking, prepare the mashed potato crust. Boil the potatoes until tender, then drain.
Mash the potatoes with butter, milk, dill, and salt until smooth and creamy.
Remove the meatloaf from the oven and spread the mashed potatoes evenly over the top.
Return to the oven and bake for an additional 15 minutes, or until the mashed potatoes are lightly browned.
Let the meatloaf pie rest for a few minutes before serving.