Most recipes promise caramelised onions in ten minutes. In ten minutes you get golden onions — good, but not caramelised. The real thing, soft, deep brown and almost jammy, takes 30 to 40 minutes. The good news: you have almost nothing to do in that time.
For a good bowlful
- 4 large yellow onions, thinly sliced into half-moons
- 20 g butter and 1 spoon of neutral oil
- A good pinch of salt
- A little water
Use a big enough pan: four onions shrink enormously, but at the start they fill a 28 cm — which pan size to choose.
The method
- Medium heat, butter and oil. The oil keeps the butter from burning during the long cook.
- The onions and the salt. Salt helps them release their water at the start. Stir to coat them well.
- 10 minutes on medium, stirring now and then. They soften, turn translucent and shrink by half.
- Drop to medium-low, 20 to 30 minutes, stirring every 3 to 5 minutes. They go from blond to golden, then to brown.
- When a brown layer forms on the base, add a tablespoon of water and scrape with a wooden spoon. The layer lifts and goes back onto the onions. Repeat each time it catches.
- They're ready when they're a deep mahogany brown, soft, and taste sweet with no bitterness.
The water trick
The brown that sticks to the base isn't burnt: it's caramelised sugar, the best of the flavour. A spoon of water puts it back onto the onions. It's the same principle as deglazing, repeated five or six times.
The three mistakes
High heat to go faster. The onions burn on the outside before they soften, and turn bitter.
Adding sugar. No need: onions have plenty. Added sugar burns fast and tastes of caramel, not onion.
Leaving a black base. If it smells burnt, turn the heat down straight away and lift it with a little water. A base that's already black, though, can't be rescued: it will make them bitter.
What to use them for
In a burger with a homemade patty, on a tart, in an omelette, with a pork chop, or as the base of a sauce. They keep 4 to 5 days in a closed jar in the fridge, and freeze very well in small portions.
Forty minutes of gentle cooking, with a base that catches and then lifts: exactly what stainless does well. The pan we film with is 304 stainless with no coating, with the 25-recipe book free.
