Combine all ingredients (except brandy/port, if using) in a large saucepan over medium heat. Do not boil the wine, as this can cook off the alcohol and alter the flavor.

Gently heat the mixture, stirring occasionally, until the honey or maple syrup is dissolved and the wine is steaming. This should take about 10-15 minutes.

Once heated through, reduce the heat to low and let it simmer gently for at least 15 minutes, or up to an hour, to allow the flavors to meld and deepen. The longer it simmers, the more intense the spice flavor will become.

If using brandy or port, stir it in during the last 5 minutes of simmering.

Before serving, carefully strain the mulled wine through a fine-mesh sieve into mugs or heatproof glasses to remove the spices and fruit slices. Discard the solids.