In a medium-sized mixing bowl, combine the shredded chicken with the BBQ sauce, ensuring the chicken is thoroughly coated. Set the mixture aside to allow the flavors to meld.
In a large skillet, heat 1 tablespoon of olive oil over medium heat. Once the oil is shimmering, add the thinly sliced red onion and bell pepper. Sauté the vegetables for about 5 minutes, or until they become tender and caramelized. Once cooked, remove them from the skillet and set aside.
In the same skillet, lay one flour tortilla flat. Evenly sprinkle half of the shredded cheddar and mozzarella cheese over the entire surface of the tortilla.
Spoon half of the BBQ chicken mixture onto the cheese layer, followed by half of the sautéed red onion and bell pepper. Top with an additional sprinkle of cheese for extra melty goodness.
Carefully place another tortilla on top and gently press down. Cook the quesadilla in the skillet for approximately 3-4 minutes, or until the bottom tortilla turns a delightful golden brown. Use a spatula to carefully flip the quesadilla and cook the other side for another 3-4 minutes until the cheese has melted and the tortilla is golden and crisp.
Once cooked, remove the quesadilla from the skillet and repeat the process with the remaining ingredients to create a second quesadilla.
Allow the cooked quesadillas to cool for about a minute. Then, using a sharp knife, slice each quesadilla into wedges for easy serving.
Garnish each plate with a sprinkle of freshly chopped cilantro. Serve the quesadilla wedges alongside a dollop of sour cream or guacamole for dipping.
Notes
Arrange the wedges on a colorful platter, drizzling a bit of extra BBQ sauce over the top if desired. A sprinkle of additional cilantro can add a nice visual flair.