- 2 onions, or more if you've got them
- 2 tablespoon butter or olive oil
- 1 tablespoon balsamic vinegar, or water or stock
Slice the onions into half moons. Melt the butter in a large, heavy-bottomed pan, add the onions and stir to coat with butter. Turn down the heat to low and leave to cook. Stir every 5 to 10 mins. They will take up to an hour, depending on the quantity of onions used. Make sure you scrape and mix in the juices on the bottom of the pan, as it adds flavour to the onions. Deglaze the pan with the vinegar/water/stock and mix well. Season to taste. Cool and store - up to a week in the fridge or freeze.