Preheat the oven to 190°C. Line a roasting pan with foil bringing it up over the sides.
Score the skin of the pork as for a ham. Place the pork in the centre of the lined pan. Combine the honey, garlic and ginger and brush firmly over the pork.
Roast for 10 minutes then reduce the temperature to 170°C for 30 minutes per 500g or until the internal temperature is 71°C
Meanwhile, place the pineapple in a nonstick frying pan. Drizzle with the combined brown sugar, oil and vinegar. Simmer over low heat for about 10 minutes. Turn the slices over and simmer until almost all the liquid has evaporated.
Cover and rest the pork for 15 minutes before carving. Serve with the pineapple.