Add melted butter, salt, and pepper to a bowl and mix. Coat the chicken breasts with butter on both sides and place in the air fryer, cooking for 10-15 minutes and flipping halfway. They are done when they hit 165 degrees internally. Let chicken rest for at least 5 minutes.
Meanwhile, start putting together the pineapple sauce by mixing the pineapple juice, brown sugar, soy sauce, minced garlic, and ginger in a small saucepan on medium heat and simmer for 5 minutes.
Mix together the cornstarch and water in a separate bowl and mix into the sauce. Let simmer for 1 more minute while stirring then remove from heat.
Slice rested grilled chicken breasts into long strips and either coat chicken entirely with sauce or pour the sauce over top of the chicken and serve.
Add chunks of canned or fresh pineapple if desired.
This nutrition information is based on the exact products I used in this recipe. Brands and sizes of products could alter exact nutrition and should always be calculated independently.