French onion soup: patience in a bowl
Onions, stock, bread and cheese, cooked slowly until they become something far grander. The Paris classic is a lesson in waiting.
The recipe for French onion soup fits on the back of a napkin: onions, butter, stock, bread, cheese. The most important ingredient is not on the list at all. It is time.
Give a pan of onions enough of it and they turn from sharp and tearful to soft, sweet and the colour of polished wood. Rush them and you get something that only looks the part. I think this soup is the clearest lesson in cooking that patience is a flavour.
A humble soup with a grand hat
Onion soups are about as old as cooking, which makes sense: onions are cheap, keep well and grow almost everywhere. The French version became the famous one. There are tales of royal inventors, but I would treat those the way I treat most origin stories, with a pinch of salt and a little cheese on top.
The version most people picture, with its lid of toasted bread and bubbling cheese, is soupe à l'oignon gratinée. Gratinée refers to that browned crust, made by sliding the filled bowl under a hot grill until the cheese melts, blisters and catches at the edges.
In Japan, where it is a familiar café and Western-style restaurant dish, menus often call it オニオングラタンスープ, "onion gratin soup", which is a rather good description of what arrives.
Les Halles and the small hours
For centuries, Les Halles was the great central food market of Paris, busy through the night as produce, meat and fish arrived for the city's kitchens. Émile Zola set his novel Le Ventre de Paris ("The Belly of Paris") there, which tells you how the place was seen.
As the tradition goes, the cafés around the market served bowls of onion soup in the small hours: to porters and traders working through the night, and to night owls finishing an evening out. The soup earned a reputation as the thing you ate when the night was long and the morning was close.
The wholesale market moved out of central Paris to Rungis, south of the city, around 1970. The soup kept its late-night glow anyway. I like that a dish can hold on to the memory of a place even after the place itself has gone.
Patience is the ingredient
The heart of the soup is the onions, and caramelising them properly takes far longer than many recipes admit. Think in terms of the better part of an hour, often more, not ten minutes. They go into a heavy pan with butter over gentle heat, and they are stirred and watched as they slump, turn golden, and finally deepen to a rich brown.
What is happening is a slow browning of the onions' natural sugars, along with the sticky layer that builds up on the bottom of the pan. That layer is pure flavour. A splash of wine, often dry white, loosens it, and some cooks add a spoonful of brandy or sherry as well. Then comes beef stock, and a gentle simmer to let everything become one.
The topping is simple but not an afterthought. Slices of bread, usually baguette, are toasted so they can float without dissolving instantly. Then a generous blanket of grated cheese, often Gruyère or Comté, goes over the top before the bowl meets the grill.
In a way, it reminds me of how Japanese soups are built, where the stock does the real work and everything else is a supporting cast. If you are curious about that idea, the anatomy of a bowl breaks it down. The difference here is that the supporting cast includes a molten roof of cheese.
How to eat it
- Wait a moment. The bowl comes straight from the grill, and the cheese hides a lot of very hot soup. A minute of patience suits the dish.
- Break the crust with the edge of your spoon. Push down through the cheese and bread into the broth beneath, and aim to get a little of everything in each spoonful.
- Cut the strings. Melted cheese stretches. Twisting it around the spoon, or pressing it against the rim of the bowl, is the usual fix.
- Save the edges for last. The cheese that crisps and sticks to the rim is, to my mind, the best part. Scraping it off is entirely allowed.
French onion soup is proof that the plainest ingredients can become something grand when you stop hurrying them. It is a soup that cannot be rushed and should not be, and I find that a comforting thing to sit down to, at any hour.