Using a sharp knife, score pork rind at 1cm intervals in a criss-cross pattern. Place the pork, rind-side up, in a large roasting pan. Combine the rosemary and salt in a small bowl; rub salt mixture over pork. Roast pork, uncovered, for 20 minutes or until the rind starts to blister and crackle.
Reduce the oven to 160°C (140°C fan-forced). Add cider to pan; roast for 1¼ hours.
Add parsnips, garlic and stock to pan; roast, uncovered, for 45 minutes.
Cut unpeeled apples into halves; add to pan. Roast for a further 30 minutes or until apple is tender. Season mixture to taste.
Serve the roast pork with the apples and parsnips.