We are well practised in using vinegar in our preserving. Here is a quick recipe for onion jam to offer as an accompaniment to pan fried or barbecued steak. This recipe will make more than enough for one dinner; the remainder can be kept in the fridge.
1 Cut 10 medium onions into chunky dices or slices and spread across a baking dish.
2 Dissolve 1 cup of sugar into 2 cups of red wine vinegar by boiling together.
3 Pour over the onions and add 1½ cups of beef stock.
4 Add ½ cup of yellow mustard seeds.
5 Cover with tinfoil and bake in a moderate oven for 1 hour.
6 Remove the foil and leave in the oven to reduce (stirring the mix every half hour) until you get a sticky. jam-like consistency. This may take at least another hour.