Pat the chicken breasts dry with a paper towel and season them lightly with kosher salt and cracked black pepper. 

Add the olive oil, minced garlic, rosemary, and lemon juice to a large bowl (or Ziploc bag) and stir.

Add the chicken to the marinade, making sure it is coated evenly on each side. 

If you have time, cover the chicken and place it in the fridge to marinate for 30 minutes. If not, just let the chicken marinate at room temperature while you preheat the air fryer. 

Preheat the air fryer to 375 degrees F for 5 minutes. 

Shake off any excess marinade and transfer the chicken to the air fryer, making sure to place the chicken in a single layer. Place the halved lemon cut side down in the air fryer. 

Cook at 375 degrees F for 10 minutes. 

Brush each breast with melted butter. If you prefer to keep this recipe dairy free or lower in calories, feel free to leave the butter out. It will still be delicious! 

Cook for an additional 8-10 minutes, or until the internal temperature is 165 degrees F on an instant-read thermometer. 

Brush the top of each chicken breast with the pan juices from the air fryer - this is key! Don’t skip this step! If your air fryer has a basket, you may need to remove the grate on the bottom to get to the pan juices. 

Squeeze the charred lemon over the chicken and enjoy immediately with your favorite sides.