In a small saucepan, combine the soy sauce, brown sugar, ginger, sesame oil, and garlic.
Take the cornstarch and water and whisk together.
Start heating the mixture on a medium heat, adding the cornstarch mixture, and stir to combine.
Heat on medium, stirring constantly for 1 minute, then reduce heat to low and cook for 2 minutes, stirring frequently. Turn off heat and let teriyaki glaze sit for 5 minutes.
Take your salmon filets and dry with paper towels or a dish cloth. Drizzle each filet with 1 teaspoon of olive oil and rub into the surface and skin of the salmon.
Next, place the salmon skin down on a plate or parchment paper. Apply the teriyaki glaze to the top and sides of the salmon.
Place the salmon in the air fryer, skin down, leaving room between the filets so air can circulate.
Cook at 390 degrees F for 9-12 minutes, checking frequently for doneness.