Instructions

1. Place all the ingredients into a wide rimmed pot with a tight-fitting lid.
2. Place the pot on a medium heat and allow the mixture to come to the boil and stir occasionally until the sugar is fully dissolved and evenly mixed and no longer sitting at the bottom of the pot, where it would burn.
3. Simmer on a low to medium heat, with the lid on, until the onions have become soft.
4. Once the onions are fully cooked, remove the lid and drop the heat so that you have a low simmer and cook until the liquid has reduced. What you are looking for is when you can run a spatula over the bottom of the pot and you can see the trail left behind for a few second before the mixture gently recoats the bottom of the cooking pan.
5. Transfer to clean, sterile jars. Cover and label.
6. Don’t be alarmed that there will appear to be a lot of liquid in the pot as the onions cook. This is simply the liquid that has come out of the onions and once you remove the lid, this will disappear as it reduced.
7. Don’t be tempted to increase the heat to attempt to try to speed up the cooking time. This will only result in the sugars over-caramelizing and everything tasting burnt! Time is the main ingredient in this recipe – but you don’t have to stand over it. It will take time and you can be pottering away doing other things while it cooks.
8. If you find that it is too sticky at the end and the pieces of onions feel like they are glued together, don’t be afraid to add a little water to loosen the consistency. Just don’t add more vinegar, as you’ll need to cook this off again.
9. For a quick way to sterilize jars, pop them into the microwave (minus the metal lids – obviously) for 90 seconds. Done! Then you can pour boiling water from the kettle over the lids and they’ll be sterile too.