This word is said to have first appeared in a Parisian café "le bel âge" on the boulevard des Capucines in 1901. René Girard, a historian of words, tells the story very well in his work "Histoire des mots de la cuisine française" published in 1947: The bistro owner, Michel Lunarca, had a reputation as a cannibal, probably spread by his competitors in the 2nd arrondissement who did not look favorably on the arrival of this new café in vogue among high society. One day, lacking baguettes, he made a sandwich with white bread, which he offered to his customers. One of them exclaimed "Michel, what meat is in it?" The bistro owner replied with a joke: "monsieur's meat, obviously", which made the assembly burst out laughing, so much so that everyone rushed to order the sandwich from the gentleman. The next day, on the slate, the bistro owner put the “croque monsieur” on the menu.
Origin of the croque-monsieur
