1. Prepare the cabbage and cut into quarters, removing and discarding the tough remains of the stem and the very large ribs. Cut lengthwise into thin strips.
2. Peel, quarter, core and slice the apples and mix the cabbage and apples in a large mixing bowl, sprinkling them with the vinegar and a generous pinch of salt. Stir.
3. Peel the onion and chop finely; fry gently in the butter and oil in a large, heavy-bottomed saucepan or casserole dish (preferably stainless steel or enamelled cast iron).
4. When the onion is tender but not browned, add the shredded cabbage together with the apple slices. Stir well and add the wine. Cover with a tight-fitting lid and simmer gently for 40 minutes, adding a little water if necessary.
5. When the cabbage is tender, add salt if needed and plenty of freshly ground black pepper, stir once more and serve very hot.