1.Remove pork from packaging. Pat dry with paper towel. Place uncovered on a rack, in a baking dish and refrigerate overnight to dry the rind.
2.Heat butter in a frying pan over medium heat. Add onion, garlic and pancetta. Cook, stirring, for 5 minutes or until onion softens. Add pistachios and cook for 2 minutes or until lightly toasted. Remove from heat and cool slightly. Transfer to a medium bowl. Add currants and breadcrumbs. Stir to combine. Season with salt and pepper.
3.Preheat oven to 240°C. Pour boiling water over pork rind. Drain and pat dry with paper towel. Untie and unroll pork. Lay flat, meat-side up. Spread stuffing mixture over pork and re-roll firmly. Tie with kitchen string to keep shape. Rub rind with oil and salt.
4.Return pork to rack in baking dish and add enough water to pan so it is 1cm deep. Roast pork for 20 minutes. Reduce heat to 180°C and continue to cook for a further 1 hour 15 minutes until cooked through and skin is golden and crisp. Transfer to a warm carving tray, cover loosely with foil and rest for 15 minutes before slicing. Serve pork with baked parsnips.
5.For baked parsnips, preheat oven to 180°C. Line a baking tray with baking paper. Wash and quarter 2 packets baby parsnips. Place in a large saucepan of cold, salted water. Bring to a simmer over medium heat and cook for 2 minutes. Drain. Rinse under cold water and dry well with paper towel. Toss in 3 tbs oil, salt and pepper. Transfer to a baking tray in a single layer and roast for 35-40 minutes, turning occasionally, until golden and tender. Serve.