Start by slicing the bell pepper and onion into thin strips. This will help them cook evenly and mix well with the chicken.
In a skillet, heat 1 tablespoon of olive oil over medium heat. Add the sliced bell pepper and onion, and sauté for about 5 minutes until they are softened and slightly caramelized.
In a bowl, combine the shredded chicken with garlic powder, cumin, chipotle chili pepper, salt, pepper, and the juice of 1/2 lime. Mix well to ensure the chicken is evenly coated with the spices.
Add the seasoned chicken to the skillet with the sautéed vegetables. Stir everything together and cook for another 3-4 minutes until heated through.
On a clean surface, lay one large flour tortilla flat. Sprinkle half of the grated cheddar cheese on one half of the tortilla, followed by the chicken and vegetable mixture, and then top with the remaining cheese. Fold the tortilla over to create a half-moon shape.
In the same skillet, add 1 teaspoon of olive oil and heat over medium-low. Carefully place the folded quesadilla in the skillet and cook for about 3-4 minutes on one side, until golden brown and crisp. Flip and cook for another 3-4 minutes on the other side.
Once cooked, remove the quesadilla from the skillet and let it cool for a minute before slicing it into wedges. Serve with a dollop of sour cream and guacamole on the side, and sprinkle with fresh cilantro for an extra burst of flavor.