In a large bowl, combine the ground beef, breadcrumbs, chopped onion, milk, egg, salt, pepper, allspice, and nutmeg. Mix well until the ingredients are just combined.

Using your hands, shape the mixture into small meatballs, about 1 inch in diameter. This should yield around 20 meatballs.

In a large skillet, melt the butter over medium heat. Add the meatballs in batches and cook until browned on all sides, about 7-10 minutes. Remove the meatballs from the skillet and set aside.

In the same skillet, sprinkle flour and cook for 1 minute to remove the raw taste. Gradually whisk in the beef broth, then add the heavy cream and soy sauce. Let it simmer for 3-4 minutes, stirring continuously until the sauce thickens.

Add the cooked meatballs back to the skillet, ensuring they are coated in the sauce. Cook for an additional 5-10 minutes, allowing the flavors to meld.

Garnish with fresh parsley and serve over mashed potatoes or egg noodles for a classic presentation.