For the chicken: Heat a seasoned grill or nonstick pan until warmed and add some oil if using. Sprinkle the chicken breasts with the salt and pepper. Cook the breasts for 2 minutes on the first side, and then flip and cook for 2 minutes more. Flip again to the first side and cook 2 minutes. Flip one last time and cook for 2 minutes more (the total cooking time will be 8 minutes). Allow the chicken to rest and cool before slicing on the bias, cutting four to five slices from each breast.
For the mayo: Whisk together the mayonnaise, lemon juice, chipotle puree and salt in a medium bowl, mixing well.
For the wraps: Apply about 1 tablespoon of the mayo to the center of each tortilla. Next, add some lettuce, sliced chicken, tomato and avocado, and then fold the ends in to the center to seal. Finally, bring the flap side of each tortilla over and roll to create sealed sandwich wraps. Slice on the bias and serve.