This is a great recipe for parties. I freeze the leftovers; they reheat quite well. The zesty chicken and cooked peppers are a succulent delight when mixed with the melted cheeses. Cut the quesadillas into wedges and serve with sour cream and salsa.
Preheat the broiler. Place baking paper on baking pan. Preheat oven to 350 degrees F (175 degrees C).
Toss the chicken with half of the fajita seasoning in zip lock bag, then spread onto the baking sheet. Place under the broiler and cook until the chicken pieces are no longer pink in the center, about 5-10 minutes. (or you can stir fry them in a pan (but I think the oven way is quicker).
Heat the oil in a large saucepan over medium heat. Stir in the green bell peppers, red bell peppers and onions and sprinkle with fajita mix. Cook and stir until the vegetables have softened, about 10 minutes. Not too soft, they get softer after taking off stove.
Spread one layer of the chicken and vegetable mixture on half of a, then sprinkle with the Mexican cheese and fold other half over (like a half moon). Brush on butter or a little oil on one side of the tortilla and fry in a pan on heat "7" so that it gets a little crisp. Flip in pan until cheese melts. Cut in half and serve.
You can make the meat and vegetables ahead of time (put in separate bowls) and then assemble them and fry 30 minutes before guests arrive. Can be easily reheated in the microwave.