Preheat the oven to 375°F (190°C).

In a large mixing bowl, combine ground beef, breadcrumbs, chopped onion, egg, garlic powder, salt, black pepper, and Worcestershire sauce.

Gently mix the ingredients until combined, then roll into 1 to 1.5-inch meatballs.

Place meatballs on a parchment-lined baking sheet and bake for 20-25 minutes.

In a medium saucepan, melt butter and whisk in flour, cooking until light brown.

Gradually whisk in beef broth until thickened into a smooth gravy.

Peel and cut potatoes, boil in salted water for 15 minutes or until fork-tender.

Drain potatoes, return to pot, and mash with butter, milk, and salt until creamy.

Gently combine cooked meatballs with gravy and serve over mashed potatoes.