"Quesadillas" are an old snack item from Mexico. In central and southern regions of Mexico they used "Corn Tortillas" for making the quesadillas. They were folded over a simple filling of cheese. They later were also filled with potatoes and chorizo. The cheese filled ones would also have a few strips of Poblano chile and fresh epazote leaves. The cheese used was braided Oaxaca cheese.
Up north in Mexico and in the southwestern USA, the flour tortilla was used mostly. Typically cooked on a "Comal" (also used to prepare tortillas) in Mexico, they like using a stringy cheese. Up north it is usually Chihuahua cheese that is used. Again a stringy cheese that melts well.
Another dish they made was a "Sincronizada" which used 2 tortillas. A popular one had ham and cheese between the tortillas. These were then cut into wedges and served.
In the southwest USA, the popular cheeses were Monterey Jack, Colby Jack and Cheddar. Which is how it is now throughout the whole USA today.
Today in the states you can find quesadillas filled with almost anything. Tradition still has them cut into wedges. They are now traditionally served with salsa (all types), guacamole and sour cream,
So you're only limited by your imagination and available ingredients as to what quesadillas you will make and/or consume. Have fun creating or even just trying those offered in restaurants. Remember that I started by saying they were a snack in the beginning. Today they can be a snack, an appetizer or even a full meal.
The recipe tomorrow is for "Classic Cheese Quesadillas" and you can expand them from there. Thursday's is for "Oaxaca Mushroom & Cheese Quesadillas" to give you something different.
So "Happy Cooking" and enjoy them until next week.