Braised Spiced Red Cabbage with Pears and Sultanas

1 large red cabbage
1 large onion, roughly chopped
4 pears, peeled, cored and cut into chunks
A large handful of sultanas
5 tbsp soft brown sugar
4 cloves
1 cinnamon stick
A little grating of nutmeg
4 tbsp cider vinegar
25g butter
Salt and pepper

1 - Peel the outer leaves from the cabbage. Cut into quarters, slice out the inner core then slice the cabbage as finely as possible.
2 - In a large casserole dish, combine the cabbage with all of the remaining ingredients. Place on the lid and cook for 2-3 hours, checking and stirring every 30 minutes to ensure that it isn't going dry. If it is, stir in a little water.