In a liquid measuring cup or small bowl, stir together the mayonnaise, lemon zest and garlic. Season with salt and pepper, to taste.
Transfer half of the mayonnaise mixture (about ¼ cup) to a new shallow bowl or plate. Stir in the smoked paprika, rosemary, red-pepper flakes and ½ teaspoon black pepper into the sauce mixture in the shallow bowl.
Take the chicken breast and butterfly it (cut it in half lengthwise), especially if it is a thicker chicken breast. If yours is thinner, you could use two chicken breasts. My mayo mixture was able to completely cover two halves of one chicken breast.
Season the chicken with salt, to taste. Add the chicken to the bowl of paprika-mayonnaise, and cover the chicken completely with the mixture.
Cook the chicken
Preheat the air fryer for 5 minutes at 400 °F.
Place the chicken breasts in a lightly sprayed air fryer basket (or on top of parchment paper).
Cook the chicken in the air fryer basket at 380 °F for 8-12 minutes, flipping at the halfway point. Chicken is done when it registers at 165 °F, can pull it out around 160 °F and tent it for several minutes to let it come to temp.
Cook the fries & fry sauce
Once chicken is done, keep it warm in covered foil. Then cook frozen french fries in the air fryer basket at 380 °F for 8 to 10 minutes, or until they are crispy and hot to your liking. Spray oil on fries to help them get crispy.
Add about 1 tbsp lemon juice to the other half of the mayo-paprika sauce. Enjoy the Chicken and fries with the remaining sauce.