Pre-heat oven to 220°c. Heat butter and oil in a frying pan over medium heat. Add the onion and bacon, cook, stirring, until bacon is cooked. Add the chicken stock and bring to the boil. Remove from heat. Combine stuffing mix and onion mixture in a bowl. Add parsley and stir to combine. Set aside to cool.
Place the pork loin, rind-side up, on a clean surface. Pat dry with paper towel. Turn pork over and use a small, sharp knife to make a 5cm-deep cut under the eye of the meat to make a cavity for the stuffing. Place the stuffing across the centre of the pork. Roll pork to enclose the filling. Secure with kitchen string, tying at 2cm intervals. Place in a roasting pan. Drizzle with remaining oil and sprinkle with salt. Use your hands to rub into the rind. Roast in oven for 30 minutes. Reduce heat to 180°C and roast for a further 45 minutes or until pork is tender. Remove from heat and cover with foil. Set aside for 15 minutes to rest.
Heat Gravox Roast Pork Gravy according to packet instructions. Transfer pork to a platter. Serve with roast vegetables and or salad and Gravox Roast Pork Gravy.