Remove the tough outer leaves from the cabbage, wash and core the head. Slice the head in half from top to bottom. Laying each half down on a cutting board, slice the cabbage in big thick slices or finely cut thin slices. Really depends on how you like your red cabbage.
Preheat a large pan, big enough to hold all the cabbage, add duck fat or butter and when it’s good and hot, add the cabbage. Cook over medium to medium-high heat until the cabbage gets shiny but not browned.
Add the onion, red wine, sugar, red currant jelly, vinegar, cinnamon stick, and cloves to the pan.
Season with some salt and pepper. If you are using optional apples, now’s the time to add them.
Cover the pot, lower the heat and simmer for approximately 2 hours until the cabbage is “dark purple and shiny.”
Remove the onion, taste and adjust seasoning with salt and pepper and if needed, some additional sugar. You want it to be a little sweet, but not too much.
You can serve this right away with the rest of your meal but it really does get better when served the following day. Historically, this is a traditional Danish side dish served with stuffed loin of pork or goose on Christmas Day.