Croque monsieur is a French dish consisting of a toasted ham and cheese sandwich. The word "croque" comes from the French verb "croquer", which means "to bite" or "to crunch", and "monsieur" is the French word for "mister". The dish is believed to have originated in Paris in the early 1900s, and it quickly became a popular snack among the city's café-goers. Croque monsieur is traditionally made with Gruyère cheese, but other types of cheese can also be used. The sandwich is typically served with a side of fries or salad.