Preheat your oven to 400°F (200°C).

In a large mixing bowl, combine ground beef, breadcrumbs, milk, onion, garlic, egg, Worcestershire sauce, salt, pepper, parsley, onion powder, and garlic powder. Mix until well combined.

Roll the mixture into 1.5-inch meatballs and place them on a lined baking sheet.

Bake the meatballs for about 20 minutes or until golden brown and cooked through.

While meatballs are baking, boil a large pot of water and cook the potatoes for 15-20 minutes until tender.

Drain the potatoes and return to the saucepan. Add garlic, butter, and milk, then mash until smooth and creamy. Season with parsley, salt, and pepper.

To make the gravy, toast flour in a frying pan, then whisk in beef broth, soy sauce, and Dijon mustard. Simmer until thickened.

Combine baked meatballs with the gravy and serve over the mashed potatoes, garnished with parsley.