Set Air Fryer to 350°
Butter bread (I find I need to wait to butter the other piece of bread)
Add Mayo, cheese, turkey and diced mushrooms to the buttered piece of bread
Lay half the assembled sandwich, buttered side down, in the air fryer
Butter second slice of bread and lay face up in the air fryer
While sandwich is cooking "open faced" in the air fryer dice your avocados and optional onion
Once the bread is desired crispiness and cheese is melted remove the sandwich from the air fryer.
Add chopped avocados to the sandwich, add the top slice of bread and enjoy!