Add olive oil to a medium skillet over medium low heat. Add the panko breadcrumbs and ½ teaspoon kosher salt. Toast the panko for about 4 minutes or until just golden, stirring every 30 seconds to evenly brown. Transfer crumbs to a plate.
Cut chicken into ¾-inch cubes (about the size of a small dice), season with ¼ teaspoon kosher salt and freshly ground black pepper, to taste, then set up your dredging station. You should have about 60 cubes.
Place flour and ¼ teaspoon kosher salt on a large plate. Place egg in a bowl, add 1 teaspoon water and beat until uniform.
Add the garlic powder, onion powder, oregano and cayenne (if using) and black pepper, to taste, to the toasted panko and place the plate on the other side of the egg bowl.
Working with about 15 pieces at a time, dredge in flour, lightly coating all sides. Then, egg, allowing excess to drip off (I like to use tongs and wipe the excess off on the side of the bowl). Next, add the pieces to the panko mixture and coat all sides evenly, pressing crumbs to make sure they adhere evenly. Repeat with the remaining pieces.
Preheat air fryer to 400 degrees F. Spray the basket with olive oil.
Add about 30 pieces to the air fryer basket, making sure to leave space between each piece so they get crispy. Spray the top with oil.
Cook for 5 minutes, shaking the basket halfway through cook time. Serve immediately.
