Preheat the oven to 200C/Fan 180C. Boil a kettle of water.
Prepare the duck: Cut the duck into 4 quarters (if whole), season the portions of meat from all sides with salt and caraway. Put the duck in a casserolle dish/deep baking tray and add appx 1cm of boiling water (avoid pouring the water over the duck, just around it). Cover and put in the oven for 1 hour. After one hour, turn over the duck and pour some of the gravy over it, re-cover and bake for another 30 minutes. Then turn it over (into the original position), pour some more gravy over it and bake without a cover for final 30 minutes or until the meat is soft and the skins are golden and crispy.
Whilst the duck is roasting: Melt the butter in a large stock pot. Add the onion and fry it on medium heat until soft and glossy. Add the chopped cabbage and stir properly, so that all of the cabbage is greased. Add the apples and stir. Add the seasoning: all spice, black pepper, bay leaves, sugar and vinegar (1-2 tbsp, according to preference). Add 200ml of water and bring to boil. The cabbage will need about 40-50 mins to cook on low/medium heat. Keep an eye on the amount of water in the pot and stir occasionally, otherwise it can burn.
Once the duck is fully cooked and the cabbage is soft, serve with dumplings/gnocchi/boiled potatoes with a little bit of the duck gravy. Enjoy!