Preheat the oven to 200/180/Gas 6. Heat oil in a frying pan and then brown chops for 2 minutes on each side. Transfer to a plate.
Add the butter to the pan, then when melted, add the sage, onion and apple, cut side down. Saute for about 5 minutes and then transfer to a roasting tin, turning the apple halves cut side up and sprinkle them with the sugar.
Roast for about 15 minutes, adding the pork back to them for the last 10 minutes.