Prepare the Ingredients: Start by shredding the cooked chicken breast and placing it in a large mixing bowl. Add the chopped bell peppers, red onions, and cilantro to the bowl. Sprinkle in the cumin, chili powder, salt, and pepper. Mix everything well to ensure the flavors are evenly distributed.

Heat the Skillet: Place a large non-stick skillet over medium heat and add one tablespoon of olive oil. Allow the oil to heat up for about a minute.

Assemble the Quesadillas: Lay a flour tortilla flat and sprinkle a generous amount of shredded cheddar and Monterey Jack cheese on one half. Spoon the chicken mixture over the cheese, and then sprinkle a bit more cheese on top. Fold the tortilla over to cover the filling.

Cook the Quesadilla: Place the folded quesadilla in the heated skillet. Cook for 2-3 minutes on one side, or until the bottom tortilla is golden brown and crispy. Flip it over and cook for another 2-3 minutes on the other side.

Repeat and Serve: Repeat the process for the remaining tortillas and filling. Once all your quesadillas are cooked, cut them into wedges and serve with salsa, sour cream, and guacamole.