I finely slice the cabbage, but not the stalk bit, and an onion then put in a casserole dish with a good lid. I add a very small amount of water and white wine vinegar and bake in a slow oven. Keep an eye on it, it shouldn't dry out but if you feel it might add a bit more water. About an hour before I want to eat I add a small dessert spoonful of soft brown sugar, a peeled finely sliced and chopped cooking apple and a pinch of caraway seeds and stir well. I don't use sultanas or raisins. freezes fine.
You’ll have to ignore all the initial waffle about trying other recipes and scroll to find her one at the end, but it’s absolutely fab. Freezes really well (actually I think it’s betterfor being frozen and reheated!) and I don’t bother with the red currant jelly as I don’t think it needs it. But it’s my default recipe and always goes down well.