Exactly what constitutes a quesadilla varies from region to region and between the U.S. and Mexico and is not universally agreed upon by chefs. And one thing you don't want to get started is a culinary argument between passionate chefs.
In most regions of Mexico, a quesadilla is a circle of cooked corn masa, called a "tortilla", folded in half and filled with cheese, then cooked until the cheese has melted. However, variations include the use of wheat flour tortillas, especially in the northeast part of Mexico, which are more like cheese tacos found in the U.S. Wheat dough is most commonly used in place of corn masa. Wheat tortillas are also used to make a gringa, which is a cross of a taco al pastor and a quesadilla.
While cheese is the most common filling, other ingredients are also used in traditional Mexican quesadillas, including cooked vegetables, mushrooms, and meat. Santiagos fill theirs with roasted poblano chilies, diced tomato, green onion and your choice of shredded chicken, beef or pork. This is accompanied by three tasty dips: chepotle ranch, ancho chili and our house-made guacamole