Grate the zest from the orange and add it to a pan along with the juice from the orange. Add the cranberries, sugar and spices. Bring to the boil, stir and cover.
Simmer gently for 5-10 minutes until the cranberries have burst and most of the liquid has evaporated. As the sauce cools, it will thicken more.
Notes
If you'd prefer to use a non refined sugar, substitute 3 tablespoons of either honey or maple syrup instead of sugar.
If you don't have ground cinnamon, allspice and ginger, then switch in a teaspoon of ground mixed spice. Or if you prefer, use a cinnamon stick and a little grated fresh ginger.