In a large pan or skillet on medium heat, cook the bell peppers and onion in olive oil for 5 minutes.
Add the chicken, garlic, and seasoning to the pan. Cook until chicken is done, around 10 minutes.
Put the veggies and chicken on a plate and use a towel to wipe any excess liquid from the pan.
Place tortillas in the pan. On half of the tortilla, sprinkle cheese, scoop some of the veggies and chicken on, sprinkle more cheese, and fold the other half of the tortilla over. Once the bottom starts to lightly brown, flip the quesadilla over.
When both sides are golden brown and the cheese has melted, remove the quesadilla from the heat and cut it into triangles. Repeat this process with the remaining ingredients.
Serve with black beans, avocados, or sour cream. Enjoy!