A quesadilla is a popular Mexican dish made by filling a tortilla, usually made of corn or flour, with cheese and other ingredients such as meats, beans, or vegetables. The tortilla is then folded in half and cooked on a griddle or skillet until the cheese melts and the tortilla becomes crispy. Quesadillas can be served with various toppings and sides, including salsa, guacamole, or sour cream. They are often enjoyed as a snack or a main meal and can be customized to suit different tastes and dietary preferences, making them a versatile option in Mexican cuisine.