Preheat air fryer to180ºC, for 4 minutes.
Pat the chicken dry with paper towel.
Brush completely with butter.
Season with sea salt and cracked pepper and lots of lovely fresh rosemary.
Place chicken into air fryer basket.
Cook at 180ºC, for 50 –60 minutes.
Let the roast chicken rest for a few minutes before removing carefully with tongs.