As is true of "French toast" and "French fries," "French onion soup" is not known as such in France.
Referred to most often as soupe à l'oignon, this hearty dish is a staple at weddings, when it's served at the end of the night — with the questionable goal of lining the stomach after all that Champagne. It's also a frequent offering at the restaurants dotting the 1st arrondissement near the former food market of Les Halles (dubbed the "Belly of Paris" by nineteenth-century novelist Emile Zola).
