Quarter the red cabbage and remove the core, then finely shred. Tip into a large pan with the red onion, brown sugar, cider vinegar, red wine, butter and cinnamon stick and season well. Bring to a simmer, then cover with a lid, lower the heat and cook for 1 1/ 2 hrs, stirring every so often. Remove the lid and continue cooking for 30 mins until tender. Will keep for two days, or can be frozen for two months. Reheat until piping hot.