Caramelised onions

Method

1. Put a large lidded frying pan over a low heat and add the oil and butter (if using). Add the onions with a big pinch of salt and stir thoroughly, until they’re all coated in the fat. Add 1 tbsp water, then cover and leave the onions to steam for 10 minutes, stirring occasionally.
2. Remove the lid and continue cooking the onions, stirring regularly. They’ll go from soft, to jammy, then begin to start taking on some colour. For proper caramelised onions, you need to cook them for about an hour – any less and your heat is probably too high. Once they start to take on a little colour, add a pinch of sugar to help the caramelisation process along.
3. Continue to stir and cook the onions until they’ve broken down into a brown, jammy mass. Ideally, you want to continue cooking them until they begin to regularly catch and stick to the bottom of the pan. Use a wooden spoon to scrape up the brown bits stuck to the bottom – this is called the ‘fond’ and is where the majority of the flavour comes from, but you don’t want to leave it stuck to the base of the pan for too long otherwise it will burn. Once these stuck-on bits become hard to scrape off, add a splash of water to deglaze and continue stirring and scraping.
4. Once the contents of the pan has turned to a dark brown jam, season the onions with another pinch of salt and either use in your chosen recipe or leave to cool, then cover and keep in the fridge for up to a week.