Tip the cabbage into a large pan with the sugar, vinegar, cinnamon and star anise. Season well. Put over a medium heat and bring to a simmer, then cover, reduce the heat and cook for 1 hr, simmering gently and stirring occasionally.

Remove the lid, turn the heat up to medium and continue cooking for 20 mins, uncovered, until tender and the liquid has reduced to a sticky syrup. Once cool, will keep in an airtight container in the fridge for three days or frozen for up to two months. Reheat over a low heat. Stir in the butter before serving.