If using fresh huitlacoche, the package will instruct wether it needs to be rinsed or not. For the canned simply open and use, the canned huitlacoche comes ready to use. If using the jarred version only if it comes in brine then you can drain otherwise do read the instructions on the jar but you should just be able to use as desired. If you'd like you can remove any corn silk from any of the huitlacoche you use.
Heat the oil, once hot add the onion and sauté until tender, sprinkle a little salt over the onion. Next add the garlic and the chopped chilie(s) and sauté until soft, then add the huitlacoche to the pan and season with a little salt and fresh or dried epazote. For fresh huitlacoche, cook just for a few minutes until the small pieces become soft and just start to break down easily. Make sure to stir often. Also watch the video for a visual of when the huitlacoche is cooked perfectly. Remove from the heat and set aside.
Cooking the Quesadilla:
Warm up a comal or a griddle or pan,until hot then turn the flame to medium-low. Then place a corn tortilla on it and allow to warm up for a minute, flip it over then on one half of the tortilla place the cheese. Spoon in some of the huitlacoche filling on top of the cheese, carefully fold the empty tortilla half over the filling to form a half-moon shape. Cook for a few minutes before flipping over and cooking a couple of more minutes -- all you want to achieve is melted cheese. Remove the quesadilla from the heat and set aside to continue until of the filling is used up.
Serve the quesadillas with your favourite salsa (or even hot sauce), I love pairing this quesadillas with my tomato & serrano pepper salsa. You can get that recipe here.