A quesar, often referred to as a quesadilla, is a popular Mexican dish made of a tortilla, usually filled with cheese and sometimes other ingredients like meats, beans, or vegetables. The tortilla is typically folded in half and cooked until the cheese melts and the exterior is crispy. Quesadillas can be served plain or with various toppings and salsas. They are enjoyed as a snack, appetizer, or main meal.