An essential ingredient for an authentic quesadilla is corn tortillas. Flour tortillas may be more commonly found in some areas, but authentic Mexican quesadillas always use corn tortillas. The cheese used in a traditional quesadilla is usually Oaxaca or Chihuahua cheese, both mild and stretchy cheeses that melt perfectly when heated. Next is the filling. While there are many options for fillings such as chicken, beef, or veggies, the most authentic option would be squash blossoms (or flor de calabaza).