In a medium skillet over medium heat, add oil.
Add onions, red and jalapeño peppers; sauté until just tender, about 3 minutes.
Meanwhile, heat up the corn kernels and keep them warm.
Transfer sautéed veggies to a bowl; set aside.
In the same skillet, add shredded chicken; season with taco seasoning and red pepper flakes.
Warm up chicken until ready to assemble, stirring occasionally, about 3 minutes - add more oil if needed.
Heat a large saucepan over medium heat.
When hot, place a tortilla, one at a time, and spread cheese on half of the tortilla, warm shredded chicken, sautéed vegetables, warm corn kernels, 4 slices avocado, and sprinkle with cilantro.
Fold the tortilla over half and using a spatula, press down to flatten it. Cook until the tortilla is browned and carefully flip the quesadilla over.
When both sides are browned, place quesadilla on a baking sheet and transfer to the preheated oven while cooking the others.
Slice quesadillas in thirds and serve with Fire Roasted Salsa and/or sour cream.
If using a quesadilla press...Turn the appliance on and spray the press, top and bottom, with cooking spray. When hot, place a tortilla and add all the ingredients, leaving about 1 1/2-inch from the edges.
Place another tortilla on top and close the lid. Cook until both side are brown.