1. Heat your oven to 110°C/Fan 90°C/Gas ¼. Thickly slice a few oranges widthways – the slices need to be around 1½ cm thick. Lay them on a rack placed over a baking tray. Slowly bake at the bottom of your oven for approximately 4 hrs. They’ll look dry, yet still feel a little soft and tacky. Leave them to dry at room temperature. Thread onto loops of your box string and hang on your tree. You can also try limes or slices of grapefruit. Do check in on them after 2 hrs in the oven.
2. The decorations will keep for 1-2 weeks. They are a bit too chewy to eat, so they are best left on the tree.