The Curious History of French Onion Soup, Paris's Timeless Hangover Cure

If you ever attend a wedding in France, don’t be surprised if long after cake has been served, someone offers you a bowl of French onion soup.

Why? Because onion soup has long been deemed a hangover cure, the French equivalent of a 2 AM slice of pizza or falafel wrap. It’s a tradition that may have gotten its start at the ancestor of the world’s largest food market in Paris.

The market known as Les Halles was founded in 1135 by King Philippe-Auguste. Starting as a simple open-air food market, it quickly blossomed, and soon a wall was required to keep it separate from its neighbor: the Saint Innocents Cemetery. But as the market grew and expanded, the cemetery began to descend into the grotesque; it grew so putrid that it was rumored to be blessed with magical “flesh-eating” soil that made bodies bury there decay in a matter of weeks.

By the 18th century, writer Louis-Sébastien Mercier was arguing that the cemetery was “attacking” the life and the health of inhabitants of the neighborhood, with such a stench of putrefaction that “broth and milk spoiled in a few hours in the houses neighboring the cemetery.” By the early 19th century, the city was forced to relocate the bones of the cemetery to the Catacombs, leaving space for the market to develop into what novelist Emile Zola would call “the belly of Paris.”

With nearly 25 acres of covered market halls, Les Halles attracted people from all walks of life: not only professionals—vendors and purchasers of wholesale goods for the thriving restaurant and grocery industries—but also Paris’ poorest residents, who were drawn to what Philippe Mellot calls in his book, La vie secrète des Halles de Paris, “an immense pantry.”

Once at the market, the poorest of the poor partook in arlequins; these plates sold by servants were filled with leftovers from massive banquets and got their names from their multicolored appearance (like Harlequins) due to appetizers, main courses, and desserts being combined on one plate.

Those who had a bit more to spend could opt instead to patronize outdoor soup-sellers, which Émile Zola illustrates so vividly in his novel Le Ventre de Paris:

This soup, while certainly warming, was often watery and, according to French author Alexandre Privat d’Anglemont, owed its rich color and appearance to the addition of carrots, caramel, or even burned onions—long the core element of the soups of France’s poor.

Onion soup has been in France’s culinary repertoire for so long that it’s nearly impossible to know how it was first invented. While some attribute the recipe to King Louis XV who, returning from a hunt, saw his cupboards were bare except for onions, butter, and Champagne (serious First World problems), others claim Louis got the idea from Stanislas Leszczynski, duke of Lorraine and father of the Queen Consort of France. According to this version, Stanislas first tasted onion soup at an inn in the Champagne region. He found it so delicious that, according to Alexandre Dumas’ Grand dictionnaire de cuisine, he asked to see how it was made. While “the smell of the onion […] brought great tears to his eyes,” he managed to copy down the whole recipe.

In reality, onion soup likely predates both Louis and Stanislas by centuries; an early version appears in Taillevent’s 14th-century cookbook Viandier, calling for cooking thinly sliced onions in butter and topping them with pea puree or water and verjus.

Wherever the original recipe came from, however, it was in the restaurants surrounding les Halles—the Poule au Pot, Chez Baratte, the Pied de Cochon—that this soup gained its acclaim, thanks to the addition of one key element: the gratinée.

“Basic onion soup—beef jus, broth, onions, and bread, is a food of the people that’s been around for a long time,” explains José Dufour, manager of the Pied de Cochon. “It was really very cheap; it was the soup of the poor.”

But by adding a heavy dose of grated cheese and placing the bowls under the broiler, these restaurateurs created the classic Gratinée des Halles (or “French onion soup” to Anglophones), a dish that transcended class distinctions. The soup became both breakfast for the forts des Halles, the workers who got their name (literally, the strong men of les Halles) from the physical strength their job required, as well as a hangover cure for well-off fêtards leaving Paris’ cabarets and drawn to the only truly nocturnal neighborhood in Paris.

“At the time, there was this ambiance at the Halles,” says Dufour. “You had butchers working in their white aprons, covered in blood, and then you had people who had just from an evening out, women in evening gowns, gentlemen in tuxedos. So bit by bit, there was this mix of people from all walks of life.”

This neighborhood no longer lives at night; the Halles market was moved from Paris to Rungis, near Orly airport, in the 1970s, and slowly, this part of Paris became like any other. Restaurants that used to open at sundown and close at sunrise began to serve meals during the daylight hours; the Pied de Cochon was the first to do so, and today remains one of the rare Parisian establishments open 24 hours a day.

But despite the loss of its nocturnal nature, French onion soup remains the Pied de Cochon’s star dish.

“This is the dish – the gratinée – that has never left our menu,” says Dufour, who notes that the restaurant sells between 150 and 200 bowls every day, still to a great variety of clients.

“You have the more festive clients, those who come as they’re leaving nightclubs, or even before they go out, but you also have people who work at night and who come here at the end of their shift,” says Dufour. “People who work in hospitals, police, people who work for the SNCF [rail company].”

And of course, there are a fair number of tourists: the Pied de Cochon has become a destination of sorts, drawing visitors to Paris from all over the world, keen on tasting the simple concoction of slowly caramelized onions, rich beef broth, day-old bread croutons, and a hearty portion of Gruyère cheese.

But restaurant customers are not the only ones to enjoy this soup. For the past ten years, Au Pied de Cochon has also worked with its neighbor, Saint-Eustache Church, to provide its famous dish to the neighborhood’s poor.

“What we call the ‘Day of the Soup’ is a meal that’s always served the second Sunday of January,” explains President of la Soupe Saint-Eustache, Gérard Siebel. “Everyone gets together in the church, and we serve a meal, and the Pied de Cochon makes onion soup for 400 people, sometimes more.”

Les Halles, as they were, are imperceptible in the modern neighborhood. The name of the metro stop is the only indication that the covered market once stood here. But onion soup, in spite of or by virtue of its simplicity, remains—an echo of the past.

“You can’t put it into a social category,” says Dufour. “If you’re one of the haves or one of the have-nots, soup is for everybody.”