Prepare the Meatballs:
In a large mixing bowl, combine the ground beef, breadcrumbs, milk, finely chopped onion, beaten egg, ground nutmeg, ground allspice, salt, and pepper. Mix until well combined.
Shape the mixture into small meatballs, about 1 inch in diameter.
Heat the vegetable oil in a large skillet over medium heat. Add the meatballs and cook until browned on all sides and cooked through, about 8-10 minutes. Remove the meatballs from the skillet and set aside.
Prepare the Sauce:
In the same skillet, melt the butter over medium heat. Add the flour and whisk continuously to form a roux, cooking for about 1-2 minutes.
Gradually add the beef broth while whisking continuously until the sauce is smooth and thickened.
Stir in the sour cream and season with salt and pepper to taste. Let the sauce simmer for a few minutes until it’s well combined and smooth.
Cook the Noodles: