Hydrate bread crumbs in a mixing bowl by pouring water (1/2 to 3/4 cup) over them.
To cook en papillote (in the oven, enclosed in foil), use a large foil oven pouch, or make an oven pouch out of a 3 foot length of heavy duty foil by bringing the 2 ends to the center, folding the sides to seal, and leaving an opening at the center through which to place the sauce and meatballs. Shake flour in the pouch to coat the inside, and (for safety reasons) place in a roasting pan. Preheat oven to 450 degrees F.
To cook en papillote on the grill, follow the same procedure with the foil pouch and preheat grill to medium-high heat. (The foil pouch method is great for cooking and cleanup, but because the liquids inside will become very hot, use a roasting pan to support the weight of the pouch for safety reasons.)
To the bowl of hydrated bread crumbs, add ground beef, onion, egg, salt, pepper, nutmeg, and allspice. With an electric mixer, beat the meat mixture until fluffy. Heat oil in a large skillet to sear off meatballs. (In the episode, we seared the meatballs in a deep-fryer.) Form meat mixture into small meatballs, and sear them in the skillet or deep-fryer. Remove to paper toweling to drain briefly. Add butter, beef stock, sherry, cream and bay leaf to foil pouch (which you have placed into a roasting pan for safety reasons to support the weight of the "floppy" pouch). Transfer meatballs to the oven pouch and seal the pouch. Bake for about 20 to 25 minutes, or grill for about 15 to 20 minutes. Use extra care in dealing with the hot liquids in the foil pouch or oven bag.
Pour the sauce from the bag into a small saucepan. Remove bay leaf from sauce before serving. Whisk in Dijon mustard and honey mustard and heat for a few minutes to thicken, and serve with meatballs.
Recipe courtesy of Robert Irvine with Brian O'Reilly, Harper Collins Publishers, copyright 2007, All Rights Reserved