I came across this marmalade in the U.K. and quickly sought out a recipe as it is very delicious with deli meats and cheeses. This recipe makes just under 4 cups worth and is so easy to do.
This recipe comes from the River Cottage Preserves Handbook and is absolutely scrumptious and keeps really well. I believe it works with white onions too.
100ml olive oil
2kg red onions, peeled and finely sliced
200g turbinado sugar
150g redcurrant jelly
300ml cider vinegar
50ml balsamic vinegar
1 rounded tsp salt
1/2 tsp freshly ground black pepper
Heat the oil in a large pan.
Add the onions, reduce the heat and cook, stirring occasionally, for 30-40 minutes until the onions are collapsed and starting to colour.
Add the sugar and redcurrant jelly. Increase the heat and continue to cook, stirring more frequently, for about 30 minutes until the mixture turns a dark, nutty brown and most of the moisture has been driven off.
Take off the heat and allow to cool for a couple of minutes before adding the vinegars to avoid them evaporating.
Return to the heat and cook rapidly for another 10 minutes, until the mixture becomes gooey and a spoon drawn across the bottom of the pan leaves a clear track for a couple of seconds.
Remove from the heat, season with salt and pepper and spoon into warm, sterilised jars.
Seal with vinegar proof lids.
Use within 12 months - though to be honest I could eat a jar of this at a single meal!