This marmalade goes with almost everything, but something magical happens when you add it to cheese.

400g plums
400g red onions
250g brown sugar
1 tablespoon grainy mustard
100ml balsamic vinegar
1 tablespoon olive oil
salt and black pepper

Chop the onions or cut into fine slices. Stone and quarter the plums.

Drizzle the oil into a pan and place over medium heat. Add the onions, cover with a lid and cook for 10 minutes or until soft, stirring occasionally. Add the sugar, plums, mustard and balsamic vinegar and continue to cook with the lid off.

Let it cook for about 20 minutes, occasionally stirring, until most of the liquid has evaporated and the mixture thickens.
Add salt and pepper to taste.

Turn off the heat and transfer into glass jars.