Like some favorite Japanese dishes may have an origin in China, many so-called South-Western cuisines in the U.S. are derived from or influenced by Mexican cooking. Quesadilla is one of these and a perfect bar food. Essentially, a cheese sandwich using tortillas. There is no real recipes. You can make many variations depending on types of cheeses and other proteins such as cooked shredded chicken, pork etc. My Mexican friend tells me that the authentic quesadilla is made from one tortilla and folded in half into a half-moon shape but using two tortillas may be more efficient. I just wanted to make a small amount for two of us this time, so I made it from one tortilla.