Recipe: French onion soup

With slow and steady cooking, this classic soup is guaranteed to melt your heart

How many recipes begin with the line ‘First, soften the onion for five minutes’? Millions, probably: and they’re all lying to you. Chopped or sliced onions simply don’t ‘soften’ in that amount of time, and caramelising takes far longer. It’s unfair: at best, the recipe takes the maker significantly longer than they anticipated or set aside, or at worst, causes the maker to serve a dish on a basis of almost-raw onions, crunchy and astringent.

This week, an old article has been doing the rounds on Twitter again, about the lies that recipe writers tell us about caramelising onions. It sent food Twitter into a spin – understandably – all of whom were in agreement: you can’t get onions soft and translucent in five minutes, and you certainly can’t caramelise them in 10. It’s a fib sold to recipe readers because it makes dishes look quicker and simpler than they actually are.

At almost the exact moment that this article was causing a furore, I was making French onion soup. French onion soup is the king of caramelised onion recipes: so much of the flavour comes from those slow-cooked onions. French onion soup should be deep and rich, and – although it’s tempting to think of it as a vehicle for generously cheesed, stringy toasts, that are just the right amount of soggy – it’s the sweet-savoury onions that are the star.

So I make no bones about this recipe: to make a French onion soup properly, you need to cook the onions for two-three hours. I know, it’s a horribly long time. And although you don’t need to hover over the stove for every moment, you do need to be in the vicinity, ready to stir and shove every 10 minutes or so. This isn’t a hands-off dish. If you’re clockwatching, this probably isn’t the soup for you; come back to it when you have a lazy Saturday morning and some telly to catch up on.

There’s no substitute for patience; there are no shortcuts for French onion soup.

Actually, that’s not true, there are shortcuts, but I don’t like them. Your first option is to add sugar to the raw onions: sugar will speed up the caramelisation – but you risk not being able to taste to check sweetness levels; for French onion soup, sugar is as much a seasoning as salt, and to chuck it in at the beginning, puts me a little on edge – and anyway, there should be enough natural sugars in the onions for them to caramelise and sweeten unaided. Or, you can add bicarbonate of soda, which increases the pH levels of the onions, meaning they will brown quicker, but you run the risk of that distinctive bitter bicarb fizz if you’re heavy-handed. Bicarb will also cause the onions to mush down into a paste, which may be less of an issue than the bitterness, but I prefer my onions soft but defined in this soup.

Take it slow, do it properly, and you will be justly rewarded.

I make this soup with a little jug of water beside me and, whenever the onions begin to stick to the pan, I add a splash of water, and scrape the bottom of the pan, dissolving the stickiness – de facto deglazing, I suppose. This won’t save you if you have truly ignored and obliterated your onions, but if your pot is slightly uneven, or your heat a little to high, it will give you a bit of leeway. It goes like this…

French Onion Soup

Makes: Enough for 4
Takes: 3 hours
Bakes: No time at all

1 kg brown onions (unpeeled weight)
40g butter
1 tablespoon olive oil
2 tablespoons plain flour
100ml Sherry
1 tablespoon balsamic vinegar
800ml beef stock
4-8 slices of French stick
150g gruyere

1. Peel, top and tail the onions and cut into slivers. Melt the butter with the oil in a large heavy-bottomed pan. Put the onions in the pan, and stir so that everything gets a good coating of the butter. Knock the heat down as low as you possibly can and let the onions begin to cook.
2. Stir the onions every 5-10 minutes. After 30 minutes they should be completely soft, translucent but uncoloured. Keep stirring every 10 minutes or so: the onions will begin to take on colour and collapse. Keep cooking and stirring until they are a deep, dark brown. If, as you stir the onions, they stick to your pan, pour in just a little water, scraping at the sticky patch until it dissolves.
3. Once the onions have darkened, stir the two tablespoons of flour into the onions, and cook for a couple of minutes until the flour sizzles gently. Add the vinegar, and then the sherry, and scrape thoroughly at the bottom of the pan, picking up any bits that have stuck there. Pour in the beef stock and bring up to a simmer, cooking uncovered for 15 minutes. Taste for seasoning and adjust with a little salt or vinegar if needed; the amount will depend on your onions and your stock, so use your judgement.
4. While the soup is simmering, heat up the grill. Toast the French bread lightly either in a toaster or under the heating grill. Ladle the hot soup into ovenproof serving bowls or one large ovenproof dish, then cover with the toast and grate (very) generously with the cheese. Don’t worry if a lot of cheese misses the bread and goes straight to the soup, this is all to the good: you really want to cover the surface of the bowl with cheese.
5. Grill until the cheese bubbles and serve straight away, being careful not to burn yourself or your diners on the hot bowls or serving dish.


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