Caramelising Onions

True caramelised onions require time, patience and low heat - it cannot be rushed. Starting with raw, sharp onions, the slow application of heat converts their starches to sugars, eventually producing deeply sweet, jammy, mahogany-coloured slices that are transformed from pungent to almost confectionery in sweetness. They're one of the most powerful flavour enhancers in vegan cooking.

Step-by-Step: Caramelising Onions

1. Slice onions thinly and evenly - red, white or brown onions all caramelise, each with slightly different flavour. Brown onions give the deepest result.
2. Heat a heavy-bottomed pan (cast iron is ideal) over medium-low heat with a generous glug of oil and a pinch of salt.
3. Add the onions and stir to coat in the oil. They'll seem like a huge volume - this is normal; they reduce dramatically.
4. Cook on low-medium heat for 30 - 45 minutes, stirring every 5 - 10 minutes. Lower the heat if they colour too quickly.
5. Add a splash of water if the pan looks dry and the onions are sticking. This deglazes the fond (browned bits) and prevents burning.
6. After 40 - 50 minutes, the onions should be deep golden-brown, dramatically reduced in volume and intensely sweet. Season and use immediately or store.

Chef's Tips

• A pinch of bicarbonate of soda raises the pH and can speed up caramelisation by 10 - 15 minutes - use no more than 1/8 teaspoon or they turn mushy.
• Caramelised onions freeze beautifully in tablespoon-sized portions - make a large batch and freeze to pull out for any recipe.
• The bottom of the pan should have a dark brown layer of fond between stirs - this is flavour. Scrape it up with a splash of water when needed.

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