Place white bread in a bowl. Pour in milk. Stand for 5 minutes. Add onions, egg, chicken, ground all spice, ground nutmeg and ground black pepper. Season with salt. Mix until combined. Roll out medium-sized balls out of the mixture. Set aside.
Meanwhile, heat oil in a large pan over medium heat. Add meatballs. Fry, turning occasionally, for 7-8 minutes or until cooked through and browned all over. (Remember not to overcrowd the pan. Fry in batches if needed). Remove with slotted spoon. Set aside.
Sauce:
To the same pan over medium heat, add 4 tablespoon butter and flour. Fry, stirring occasionally, for 1 minute or until the mixture is bubbling away and browned. Whisk in chicken stock and cream. Add Worcestershire sauce and dijon mustard. Season with salt and pepper.
Bring to boil. Simmer for 4-5 minutes or until sauce is thickened. Add meatballs. Simmer for another 2 minutes. Garnish with chopped parsley.
Serve with mashed potatoes and lingonberry jam. Sub mashed potatoes with French fries, buttered egg noodles or crusty bread if you like.