Preheat the oven to 400°F (200°C).

In a mixing bowl, combine ground beef, bread crumbs, egg, garlic powder, onion powder, salt, black pepper, and parsley. Mix until well combined.

Form the mixture into meatballs, about 1 inch in diameter, and place them on a baking sheet.

Bake in the preheated oven for 20-25 minutes, or until cooked through.

While the meatballs are baking, place the cubed potatoes in a pot and cover with water. Bring to a boil and cook until tender, about 15-20 minutes.

Drain the potatoes and return them to the pot. Add milk, butter, salt, and black pepper. Mash until smooth and creamy.

In a skillet, melt butter over medium heat. Whisk in flour and cook for 1-2 minutes until golden.

Slowly whisk in beef broth and soy sauce. Bring to a simmer and cook until thickened, about 5 minutes.

Serve meatballs over mashed potatoes, drizzled with gravy.