In a large bowl, mix together the ground beef, breadcrumbs, milk, egg, salt, pepper, allspice, and nutmeg.
Form the mixture into small meatballs.
Heat a skillet over medium heat and cook the meatballs until browned on all sides. Remove and set aside.
In the same skillet, melt the butter. Stir in the flour and cook for 1-2 minutes.
Gradually whisk in the beef broth and bring to a simmer.
Stir in the heavy cream, soy sauce, and Dijon mustard. Simmer until the sauce thickens.
Add the meatballs back to the skillet and simmer for another 10 minutes.
Serve the meatballs with the sauce over mashed potatoes or noodles.