Creating BBQ Chicken Quesadilla is simple if you follow these easy steps:

1. Prepare the Chicken: In a mixing bowl, combine the shredded chicken with the BBQ sauce. Stir until well coated.
2. Heat the Pan: In a large skillet, heat 1 tablespoon of olive oil over medium heat.
3. Assemble the Quesadilla: Place one tortilla in the skillet. On one half of the tortilla, layer a generous amount of the BBQ chicken mixture and top with shredded cheese.
4. Add Vegetables: If using, sprinkle sliced red onion and bell pepper on top of the cheese.
5. Fold the Tortilla: Carefully fold the tortilla in half, covering the filling.
6. Cook the Quesadilla: Cook for 3-4 minutes on one side, until the bottom is golden and crispy. Flip and cook for an additional 3-4 minutes on the other side.
7. Remove and Cut: Once both sides are golden and the cheese is melted, remove the quesadilla from the skillet. Let it cool slightly before cutting it into wedges.
8. Repeat: Repeat the process with the remaining tortillas and filling.
9. Serve Warm: Place the wedges on a serving platter and garnish with fresh cilantro, if desired.

Following these steps will guide you to create mouthwatering BBQ Chicken Quesadilla effortlessly.