In a mixing bowl, combine ground beef, breadcrumbs, egg, milk, salt, pepper, and allspice. Mix well and form into 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 butter and whisk in flour to make a roux. Gradually add beef broth and heavy cream, stirring constantly until the gravy thickens.
Return the meatballs to the skillet and simmer in the gravy for 10-15 minutes. Serve hot.