Peel off the outer leaves from the cabbage and discard. Quarter the cabbage, removing the tough stem, then thinly slice. Arrange a layer of the cabbage on the bottom of a large saucepan, followed by some of the onions, apples, zest, mixed spice, sugar and seasoning. Continue to create layers until you have used up the ingredients.
Pour over the vinegar and cider and dot the butter on top. Bring to the boil then simmer with a lid on over low heat for
1½ hrs, until tender. The cabbage will keep for 2 days, covered, in the fridge or freeze for up to 1 month. Reheat in either a pan or in the microwave.