Caramelized onion

Slice the onions evenly and cook them in a wide, heavy pan with a little oil or butter and a pinch of salt over low to medium-low heat. Stir every few minutes for 35–50 minutes; if they start sticking before they turn brown, add a splash of water and scrape the pan.

No. Onions contain enough natural sugars to become sweet and brown during slow cooking. A pinch of sugar can speed browning, but it is not needed and can make the onions burn more easily.

Yes. Cool them promptly, refrigerate in a covered container and use within 3–4 days. Freeze in small portions for up to 3 months, then thaw in the fridge or reheat gently in a pan.

Its sweet, savoury flavour works well with mature cheese, mushrooms, thyme and mustard. Add it to a cheese toastie, savoury tart, burger or pizza, or stir it through mashed potatoes.

You can, but it brings sweetness and a soft texture rather than the sharp crunch of raw onion. Use it in cooked fillings, sauces or soups; for a fresh salsa or salad, raw onion is a better fit.

The onions need time to soften and lose moisture before their natural sugars brown. A crowded pan or high heat can make them steam or scorch instead, so use a wide pan and cook them slowly.