A Croque Monsieur is a classic French sandwich made with ham and cheese, typically Gruyère or Emmental. It is prepared by layering the ham and cheese between two slices of bread, which are then buttered and grilled until golden brown. The sandwich is often served with a side of salad or fries. For an extra touch, a Croque Madame variation includes a fried or poached egg on top. This delicious dish is popular in cafés and bistros across France and is enjoyed as a snack or light meal, showcasing the simplicity and richness of French cuisine.