A croque madame is a classic French sandwich consisting of ham and cheese, typically Gruyère or Emmental, layered between slices of bread and grilled or baked until golden and crispy. It is topped with a fried or poached egg, which distinguishes it from the croque monsieur. The creamy béchamel sauce, often added inside or on top, further enriches its flavor, making it a hearty and indulgent meal.