Firstly, place the duck onto a tray and place in an oven at 180, for about 20 minutes, or until the duck is tender and falling from the bone. Meanwhile grate the potato into a middle bowl, add the onion, egg and the flour. Shred in the duck, mix together and season. Heat the oil in a large pan and cupping the mixture, shape into patties. The mix will make about 4 depending on how big you want them. Serve on a bed of rocket, topped with a poached egg and hot sauce.