In a large, heavy-bottomed saucepan or Dutch oven, combine the apple cider, orange, sliced red and green apples, ginger, cinnamon, cloves, star anise pods and cardamom.
Bring the mixture to a gentle simmer over medium-low heat. Reduce heat to low, cover partially, and simmer for 20-30 minutes, stirring occasionally. The longer it simmers, the more intense the spice flavours will become.
After 20 minutes, taste the cider. Add a little maple syrup or honey if you feel it needs more sweetness.
Strain the mulled cider through a fine-mesh strainer into a heat-proof pitcher or serving vessel. Discard the solids.
Serve warm in glasses or mugs, garnished with a cinnamon stick, fresh apple slice, star anise pod, and a sprig of thyme or rosemary. Top each glass with a splash or two of ginger beer for a bit of fizz.