Red cabbage - chop - not too finely, boil until soft (I never salt the water - you can't really overcook it, so I often boil it for longer than necessary). Drain it - I usually leave a small amount of water in the pan. Then add vinegar. Sarsons is fine, or cider or wine vinegar. Give a good stir, put back on low heat. Then add sugar and salt. Don't be dainty with either the vinegar, sugar or salt, but add in stages, tasting as you go. It's up to you how you like it, I usually go for a sweet/sour taste, if you prefer it more sour, just add more vinegar. No apples, no cloves, no cinnamon, no onions, all done on top of the cooker, so no oven either. Add a knob of butter at the end, give a good stir and serve.
Good with roast pork, chicken, duck, goulash, bigos, most stews. Will keep, cooked, in the fridge for about a week.