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, such as salsa, guacamole, or sour cream. They are versatile and can be customized to suit different tastes, making them a favorite choice for meals or snacks.