IN a large resealable plastic bag, combine chicken and WHOLE30 Buffalo Vinaigrette. Massage to coat. Seal bag and marinate in the refrigerator for at least 2 hours and up to 4 hours.
PREHEAT air fryer* to 375°F. Remove chicken from bag; discard marinade. Add the chicken to the air fryer. Cook until chicken is no longer pink and the internal temperature is 170°F, turning once, about 15 minutes. Let stand while making the salad.
IN a large bowl, combine the romaine, celery, and carrot. Add the WHOLE30 Ranch Dressing; toss to combine. Divide salad among four serving plates.
SLICE the chicken. Top the salads with sliced chicken, avocado, and cherry tomatoes. Season to taste with black pepper. Sprinkle with chives.
*Oven method: Preheat oven to 350°F. Heat an oven-safe skillet over high heat for 5 minutes or until it is very hot (cast iron works well). Place the chicken on the hot skillet and cook for 1 minute. Cook for 1 minute, then turn and cook for 1 minute on the other side. Transfer the skillet to the oven and bake until no longer pink in the center, the juices run clear, and the chicken reaches an internal temperature of 165°F, 8 to 10 minutes.