Add a thin layer of mayo to the outside of both slices of bread.
Then sprinkle with salt and pepper.
Lay one piece of bread, mayo side down, in the air fryer.
Top with a couple slices of cheese.
Then add the other slice of bread with the mayo side facing up.
Air fry at 375°F (190°C) for 4 minutes. Then pause the air fryer and carefully flip the sandwich over. Continue to air fry for an additional 4 minutes.
Notes
I know, butter is more "normal" than mayo but trust me, mayo is best. Vegan mayo also works.Sometimes the top bread will shift off the sandwich during air frying, so if you see this, simply gently push it back in place before flipping. No big deal.