Trim and score the fat on the duck breasts with a sharp knife. Marinade with the soy sauce, Chinese five spice and chilli for 30 minutes. Seal the duck breasts in a hot pan, fat side down first for 2 minutes on each side, remove from the heat. Remove excess fat from the pan, add the sauce ingredients and simmer gently to a thick consistency, adjusting with chicken stock when necessary. To smoke the duck, place several layers of silver foil in the bottom of a thick bottom sauce pan. Mix together the rice, sugar, black tea, star anise and cinnamon and pour in the centre of the foil. Place a cooling rack on top of it making sure that the ingredients do not touch with it. Cover the pan with a tight fitting lid and place over moderate fire allowing the ingredients to start smoking. Place the duck breasts over the rack and smoke for approximately 10 minutes. Allow the duck breast to rest for a few minutes before serving. Slice and serve accompanied with the potatoes and vegetables, drizzled with the plum sauce and garnished with strips of chilli and spring onions.