The Forty-Minute Onion Revolution (and Other Soup Heresies)

French onion soup is not a recipe. It is a personality test with a ladle. It asks whether you are the sort of person who will stand at the hob for three hours stirring onions like a medieval penance, or the sort who buys a tub of pre-sliced onions and a blowtorch and calls it dinner. At La Petite Fou we are firmly in the second camp, provided the result tastes like the first. This is the done properly-ish position: respect the onion, cheat the clock, and never let a crouton float about unsupervised.

The caramelisation clock is mostly a lie

There is a certain kind of French onion soup recipe that begins with the words ‘allow three hours’. It is not a recipe. It is a lifestyle. Yes, onions will deepen and sweeten over a long, slow cook, but the idea that you must babysit them for an entire afternoon is the sort of gatekeeping that puts people off cooking altogether. In 2026, with the cost of everything from gas to Gruyère doing its best impression of a theme-park ride, we need soup that works on a weeknight.

My position is this: forty to fifty minutes is enough if you pay attention. Use a wide pan, not a tall saucepan, because surface area is everything. Slice 1.5kg of brown onions thinly — red onions are for people who enjoy disappointment — and put them in a heavy pan with 80g of butter and a generous glug of olive oil. Add a good pinch of salt straight away. Salt draws out water, which helps them soften rather than scorch. Keep the heat medium to medium-high. Stir every few minutes, scraping the brown bits back into the mix. If the pan looks dry, add a splash of water rather than more fat. That splash of water is the difference between caramelised and cremated.

Will they be as deep and jammy as a three-hour onion? No. Will they be sweet, soft, savoury and entirely capable of carrying a bowl of soup? Absolutely. The trick is to deglaze properly at the end: a slug of dry sherry or vermouth into the hot pan, scrape, bubble, then add your stock. That little hit of acid and alcohol does more for the final flavour than an extra hour of stirring ever will.

Stock cubes are not a crime, but silence is

Here is the confession that would get me thrown out of a certain type of French kitchen: I have made very good onion soup with a beef stock cube. Not a sad, watery one. A good one. The kind that dissolves into something savoury and rounded rather than salty and beige. If you have homemade beef stock in the freezer, use it and feel smug. If you do not, buy the best beef stock cube or liquid stock concentrate your supermarket offers and stop apologising.

The UK supermarket angle matters because this is where most of us actually cook. Waitrose stock is lovely if you are passing. Sainsbury’s Taste the Difference beef stock is perfectly decent. OXO cubes have a place in the nation’s heart and a place in this soup, especially if you add a teaspoon of Marmite or a splash of soy sauce for depth. A little dry sherry helps. A bay leaf helps. A sprig of thyme helps. What does not help is pretending that the only legitimate soup is one built on a stock you simmered from roasted bones on a Sunday. That is not dinner. That is a project.

The blowtorch moment

For years the blowtorch was the preserve of people making crème brûlée and people making slightly threatening YouTube videos. Now it is a legitimate kitchen tool, and French onion soup is its finest hour. You want a blistered, molten, slightly uneven cheese crust — the sort that pulls into strings and leaves a faintly burnt edge that tastes of victory. A grill can do this, but it heats the whole kitchen and often cooks the bread before the cheese has surrendered. A blowtorch is faster and more fun.

Safety note, because we are mad not reckless: use oven-safe ceramic bowls, not Pyrex, not your favourite vintage teacup, not anything you are emotionally attached to. Fill the bowl, top with bread and cheese, then torch the cheese until it bubbles and blackens in patches. If you do not own a blowtorch, the grill is fine. If you do own one and have been using it only for crème brûlée, shame on you. It has been waiting.

The crouton-to-cheese ratio is not a joke

This is where many onion soups fall apart. A crouton is a raft, not a lifebuoy. It should cover roughly two-thirds of the soup’s surface, leaving a visible moat of broth around the edge. Too small and it disappears; too large and you are eating cheese toast with a side of soup. Use a stale baguette, sliced on the bias, rubbed with garlic and drizzled with olive oil, then toasted until crisp. Do not use fresh bread. Fresh bread is a sponge, and not in a charming way.

As for cheese, the ratio should be indecent. By weight, aim for twice as much cheese as bread. Gruyère is the classic. Comté is better if you are feeling flush. In a British supermarket, a mature cheddar with a little Parmesan grated in will give you the nutty, salty pull you want without a second mortgage. Grate it coarsely. Pile it on. Do not pat it down like you are making a bed. You want peaks and edges and places for the blowtorch to catch.

The supermarket shopping list, 2026 edition

For four to six bowls: 1.5kg brown onions, 80g butter, olive oil, a good beef stock cube or liquid concentrate, dry sherry or vermouth, a stale baguette, garlic, Gruyère or mature cheddar plus Parmesan, thyme, bay leaf, salt and pepper. That is it. No truffle oil. No micro herbs. No three-hour timetable. The onions will make you cry. The soup will make you feel brave. That is the deal.

The method, properly-ish

Slice the onions thinly. Cook them in butter and oil with salt over a medium-high heat for forty to fifty minutes, stirring and scraping, adding a splash of water if they catch. When they are soft, sweet and the colour of dark honey, add a splash of sherry and let it bubble away. Add the stock — about 1.5 litres — plus thyme and a bay leaf. Simmer for twenty minutes. Taste and adjust. Toast the baguette slices. Ladle the soup into oven-safe bowls, float the toast on top, cover with an outrageous amount of cheese, and blowtorch or grill until molten and patchily blackened. Serve immediately, with a napkin the size of a tea towel and a cold glass of something white and dry.

Cry once. Cheat twice. That is the La Petite Fou way.