Heat oil in large skillet over medium heat. Add red onion and cook until fully softened, about 3 minutes. Stir in green onion and bell pepper and cook for 1-2 more minutes.
Sir in chicken, taco seasoning and water. Cook for 2-3 minutes, then take off the heat.
To assemble quesadillas, sprinkle one half of a tortilla with 2 tablespoons of cheese. Top with ¼ of chicken mixture, then sprinkle with 2 more tablespoons of cheese. Fold over and lightly brush outside with olive oil.
Heat a griddle or large non-stick skillet just over medium heat (I heat my griddle to 390°F). Cook each quesadilla around 3 minutes per side, until browned on the outside and melty on the inside.
Cut quesadillas in half to serve.
Chicken: It’s easy to make shredded chicken at home – but rotisserie chicken or pre-shredded chicken also work here.
Cheese: I use a Mexican blend, but Monterey Jack is also great. You can use shredded cheddar or a cheddar blend in a pinch, if that’s all you have on hand.
Tortilla wraps: I love using large, grilled flour tortillas from Mission for my quesadillas (not sponsored in any way, genuinely the brand I prefer). Feel free to use any brand you like, but I do recommend sticking to the same size and to flour tortillas for these.
Red onion: White onion is a good substitute if you don’t have red on hand, or simply leave it out if you are not a fan of onion.
I chop the vegetables fairly small and evenly, to make sure they fit neatly into the folded tortilla. Large chunks will keep you from neatly folding the tortillas, or may even cause the tortilla to break.
Make sure to adjust the amount of taco seasoning added to suit your taste - I will often do just 1 tablespoon because I have small kids; but you can add 2 tablespoons if you prefer a lot of spice.
We like our quesadillas nicely crispy on the outside. If you prefer yours softer, only use medium-low heat when cooking the quesadillas on your griddle or in a skillet.