Remove the pork from the roasting tray and leave to rest. Pour the remaining glaze into the roasting tray, then add the wine, Champagne or water. Place the pan on the heat and bring everything to the boil, simmer for a few mins until you have thick gravy. Carve pork into thin slices and place on top of the colcannon (see separate recipe). Glaze with the Guinness syrup, drizzle a little on the plates and finish with a sprig of parsley.