"I came up with this recipe one random day when I craving a light southwest meal. It is simple and healthy! Mix and match vegetables to optimize to your taste. It is quite easy to overfill the quesadillas, making them a disaster to flip. Fill according to tortilla size and flip carefully or use a quesadilla maker."
Heat 1 tablespoon olive oil in a skillet over medium-high heat. Saute garlic in hot oil until fragrant, about 1 minute. Add yellow squash; cook and stir until slightly softened, 1 to 2 minutes. Stir chicken and bell pepper into squash mixture; cook and stir until heated through, about 2 minutes more. Season chicken mixture with salt and transfer to a bowl.
Spray one tortilla with olive oil cooking spray and place in the hot skillet. Place 1 slice Cheddar cheese on the tortilla and spread 1/2 the chicken-vegetable mixture on top. Spoon 1/2 the black beans over chicken-vegetable mixture and 1/2 the avocado over the black beans. Sprinkle 1/2 the cilantro over the avocado. Spray another tortilla with cooking spray and place on top. Continue to cook until bottom tortilla is crispy, 2 to 3 minutes; gently flip quesadilla over and cook until cheese is melted and bottom tortilla is crispy, about 4 minutes more. Repeat with remaining ingredients to make second quesadilla.