Making Chicken Quesadilla is a simple process that can be done in just a few steps:

1. Prepare the Ingredients: If not already done, shred the cooked chicken and slice the bell pepper and onion.
2. Heat the Pan: In a large skillet, heat olive oil over medium heat. Add the sliced onion and bell pepper. Sauté until they are soft, about 3-4 minutes.
3. Season the Vegetables: Sprinkle taco seasoning, salt, and pepper over the sautéed vegetables. Stir to combine and cook for another minute.
4. Add the Chicken: Incorporate the shredded chicken into the skillet. Mix everything together and let it heat through for about 2-3 minutes.
5. Assemble the Quesadillas: On a flat surface, lay one tortilla down. Spread a quarter of the chicken and vegetable mixture on one half of the tortilla. Top it with a quarter of the shredded cheese. Fold the tortilla over to create a half-moon shape.
6. Cook the Quesadilla: In the same skillet, add a small amount of olive oil if needed. Carefully place the folded quesadilla in the skillet. Cook for about 2-3 minutes on each side or until golden brown and the cheese melts.
7. Repeat: Repeat the process for the remaining tortillas and filling mixture.
8. Slice and Serve: Once cooked, remove the quesadillas from the skillet. Let them cool slightly before slicing them into wedges.