Add all the ingredients to a slow cooker and stir to combine.
If you like warm, winter spices you can add 5-6 star anise and cloves too. Set the temperature to high and heat for one hour. Reduce the temperature to low to keep it warm for up to 5 hours. If you don’t have a slow cooker, simply place ingredients in a heavy-based casserole dish or saucepan, bring to the boil and simmer with the lid on leaving it on a very low heat for about 45 minutes without having a glass until your guests arrive! To serve, spoon into insulated glassware. Add a few seasonal berries, a stick of cinnamon and a dehydrated or fresh orange or clementine slice.
What san-gria is to summer, this crowd-pleasing punch is to winter.