Lay a piece of parchment paper on your work surface and lay the chicken breasts out in a single layer. Cover with another piece of parchment paper. (You can also use plastic wrap/cling wrap).

Use the flat side of a meat tenderizer or mallet to pound each chicken breast to about ¼-inch thick. Don't pound too aggressively as you may tear the chicken.

Set up your breading stations. Add the flour to a shallow bowl. In another shallow bowl, whisk your eggs and mustard. And, in a third shallow bowl, mix together the panko bread crumbs and seasonings.

Take a piece of chicken and lightly coat it in the flour, shaking off any excess.

Dip the floured chicken in the egg mixture, making sure it is fully coated on both sides. Let any excess drip off.

Move the chicken to the panko mixture and generously coat it, lightly pressing the crumbs into the chicken so it sticks well.

Repeat with remaining chicken.

Place the chicken pieces in a single layer in the air fryer basket and lightly spray the tops with oil. Since the chicken pieces are so wide, you will need to air them two at a time. Store the remaining two in the fridge until ready to air fry.

Air fry on 400F for 8 minutes. Flip over, spray the tops again and air fry for another 6-8 minutes, or until the chicken reaches an internal temperature of 165F.