Also called "drunkards' soup", onion soup is a very good remedy for a hangover. Of course, the sweet breath it leaves you afterward doesn't help your cause, but at least it masks the unpleasant fumes of alcohol.
In fact, onion soup has had a bad reputation for a long time. Made from meat juice, broth, onions, and bread, it has always been inexpensive. Even in ancient times, the Romans considered it a poor man's dish, hence the name "poor man's soup" (they didn’t go very far). This is because onions are easy to cultivate and therefore very accessible, especially for modest families.
A legend has given this soup a new image: it is said that King Louis XV woke up hungry at night while staying in his hunting pavilion. It is said that he prepared a soup with onions, butter, and champagne that he had at his disposal. But it's hard to imagine a king preparing his own meal... although it is said that Louis XV was a good cook!
There is a more credible theory. It is said that Stanislas Leszczynski, Duke of Lorraine and father of the Queen of France, tasted onion soup at an inn in Champagne. He then wanted to learn "how to make a similar one," according to Alexandre Dumas, who recounted the scene. Subsequently, he popularized the recipe at the court of Versailles.
However, it was thanks to Les Halles in Paris that gratinated onion soup became famous. In the 19th century, restaurateurs had the idea to add grated cheese and place the soup bowls under the grill. This made the soup much more nutritious for workers and nocturnal townspeople. The dish was then called "Gratinée des Halles".
