Prepare the cabbage by first cutting out any hard stalky bits or ribs and then shredding the leaves as thinly as possible.
Now blanch the cabbage by placing it in a saucepan of cold water, bringing it to the boil and boiling for 1 minute, after which it needs to be drained in a colander. Next, using the same saucepan, heat the butter and fry the bacon until the fat starts to run from it. Add the onions, potato, leek and garlic, stir all the vegetables around and cook them until softened and slightly golden.
Then stir in the drained cabbage and cook for another minute or two before pouring in the stock. Bring it back to the boil and then simmer very gently without a lid for about an hour. Finally taste and add seasoning and a little freshly grated nutmeg.