Rinse the cabbage well in a colander.
In a large heavy pan, fry the onion gently in the butter and oil until it starts to soften – about 5 minutes.
Add the drained (but still wet) cabbage, apple, sugar, vinegar, ground cloves and season. Cover tightly and cook over a very low heat for about 2 hours, checking and stirring every 15 minutes. You might need to add a little water if if starts to dry out and stick to the pan. It is ready when the whole mass is soft and reduced in bulk. Taste to check the seasoning – add more salt, pepper, sugar if necessary.
This side dish is ideal served with lamb shanks, duck confit or sausage and mash.