Mix the ingredients of the marinade, and add the breast fillets and legs. Refrigerate overnight. To make the stock, put carcass portions and other stock ingredients into a large saucepan. Add water to cover and bring to the boil. Simmer gently for 45 minutes. Strain, return stock to a clean pot and reduce over medium heat for 15 minutes. Remove any remaining meat from the carcass and reserve. Cool reduced stock, and refrigerate overnight. When stock is cold, skim fat from the surface. The stock is ready for use. For the duck portions: remove from marinade, and cook in a hot oven (about 200c) for about 20 minutes for the breasts, and about 30 minutes for the legs. You want the meat to be pink and juicy still, and the skin crispy. Cool a little then shred the meat. For the soup: Put stock in a large saucepan and bring to the boil. Reduce heat, and add remaining soup ingredients including both lots of reserved duck meat. Warm through and season to taste.