Onions have a strong, distinct smell. I would not categorize their smell as pleasant, but it is incredibly appetizing. I would not want an air freshener scented in onion, but the smell of cooked onions elicits an appetite in me more than any other scent. Clearly, These quesadillas are not authentic, but they are delicious.
I initially planned to use mozzarella in these quesadillas, but I saw Oaxaca queso at my favorite grocery store. For the balsamic glazed red onions, I used three large onions,2 tablespoons extra virgin olive oil, and 2/3 cup balsamic vinegar. In addition to the glazed onions, the quesadillas required queso and tortillas.
I added the olive oil to a warm pan as I finished cutting the red onions. This was all done while crying profusely; These were some potent red onions. There are too many onions in this pan, and I have heard that prevents the onions from browning properly. I added the salt and pepper and simmered the onions for 15 minutes.
After they had browned and softened, I added 2/3 a cup of balsamic vinegar. I cooked the onions for an additional 20 to 25 minutes. Traditionally, balsamic vinegar is made from white grapes that are cooked down until they have reduced down to 30% of their initial volume. The grapes are then fermented for at least 12 years. Over 100 years ago people were making balsamic vinegar in Modena, Italy.
The onions were finished when they were very soft and and brown. The moisture from the vinegar had evaporated or been absorbed by the onions. I had to have a generous sample at this point to ensure the flavor was up to par.
I prepped my quesadilla on a plate before transferring it to a hot skillet. I layered queso and then a generous scoop of onions.
I added another layer of queso on top of the onions and then toped it with another tortilla. I cooked it on both sides in a skillet until the cheese melted and the tortilla browned.
Browning the tortilla is an essential step. Don't be tempted to use a microwave to melt your cheese. Quesadillas need a little crunch. These onions are exquisite. You could put them on pizza, salad, sandwiches, and a bunch of other stuff. They are definitely the star of this dish. You could use any type of mild cheese in place of the queso.