French Onion Soup Is What Happens When a Chef Burns Onions on Purpose for an Hour

French onion soup was invented in 1651 by Gaston Fromage, a Paris cook who was told to keep an eye on the onions and took it as a philosophy. He kept an eye on them for an hour. They went brown, then browner, then a colour his guild had no word for. His employer, a marquis with no sense of smell, called it the finest soup in France, and Gaston was promoted to Head of Onions. The French Academy ruled in 1652 that the worst cook in a kitchen may make its best meal, provided he is too stubborn to stop. The ruling has never been overturned, mostly because nobody has tried.

What follows is a ladder. Each rung adds one thing. Climb until you are happy or out of wine.

The ladder

1. Fucking bad. Onions boiled in salted water. This is onion tea. It is how an onion apologizes.
2. Bad. Onions “caramelized in five minutes,” as every recipe promises. Black outside, crunchy inside: the onion’s way of saying it was rushed.
3. Fine. Onions cooked low in butter for a full hour until brown and jammy, then water. Sweet, honest, thin. Soup you could serve a cousin.
4. Good. Swap the water for beef stock. Now it has a spine.
5. Very good. Wine. One glass in the pot to lift the brown off the bottom, and, under the 1652 ruling, one in the cook. Neither is optional.
6. Fucking good. Thyme, a bay leaf, a splash of cognac, then a raft of toast under a drift of Gruyère, grilled until it blisters. The cheese should weld itself to the bowl. That is how you know.

The recipe (rung six)

Serves 4 to 6. About two hours, most of it watching.

• 1.5 kg yellow onions (about 6 large), halved and thinly sliced
• 60 g butter and 1 tbsp oil
• 1 tsp salt, plus more to taste
• 2 garlic cloves, sliced
• 4 sprigs thyme and 1 bay leaf
• 1 tbsp flour
• 250 ml dry white wine
• 1.5 litres good beef stock (low-salt if bought)
• 2 tbsp cognac or dry sherry
• Black pepper
• 1 baguette, sliced thick and toasted dry
• 200 g Gruyère, grated

1. Melt the butter with the oil in a heavy pot over medium heat. Add the onions and salt and cook, stirring every few minutes, for 60 to 90 minutes. Turn the heat down as they colour. If the bottom catches, add a splash of water and scrape. You want deep brown and jammy, not black.
2. Stir in the garlic, thyme, bay and flour and cook for two minutes.
3. Pour in the wine, scrape up everything stuck to the pot, and let it reduce by half.
4. Add the stock and simmer for 30 minutes. Fish out the thyme stems and the bay leaf, season, and stir in the cognac.
5. Heat the grill. Ladle the soup into ovenproof bowls on a tray, float the toast on top, heap on the cheese, and grill for 3 to 5 minutes until it bubbles and browns in spots.

Rung seven: the beef variant

For when the stock alone has stopped being enough beef. The marquis ate it this way on Sundays, chiefly so he could tell people he had.

• Add 700 g boneless beef short rib (or chuck), cut into 4 cm pieces, salted an hour ahead, and 250 ml more stock.

1. Before the onions, brown the beef hard in the oil in the same pot, in batches, and lift it out. Leave the fat. It is the onions’ problem now.
2. Cook the onions as above, in that fat and the butter.
3. At step 4, put the beef back with all 1.75 litres of stock, cover, and simmer for 1½ to 2 hours, until it falls apart when you look at it sternly.
4. Shred the beef with two forks, return it to the pot, season, and finish as above. Each bowl now needs a spoon and a fork, which is how you know it is expensive.

If the smoke alarm goes off at rung two, you have invented a rung of your own. Gaston would be proud. The fire brigade will not.