Pound your chicken breasts to ¼-inch (0.64 cm) thick and trim them to about 3 ounces (85 grams) each. (Or just purchase thin chicken cutlets that are the right size and save yourself a lot of work!)
Whisk the eggs and mustard together in a bowl. In a second bowl, stir together the pork panko, garlic powder, dried parsley, Parmesan cheese, salt, and pepper.
Bread each chicken piece by coating it first with the egg mixture and then with the panko mixture. Pat the panko on to each cutlet so it sticks well.
Put the breaded cutlets on an air fryer tray in a single layer. My air fryer has two trays, and I was able to cook four cutlets at a time (two per tray). I had to cook the schnitzel in two batches since there are six breaded cutlets in this recipe. If you have a smaller fryer, you may need to cook the cutlets in three batches.
Air fry the chicken for 5 minutes at 375°F (190°C). Then switch the position of the trays in the air fryer oven (don’t flip the chicken). Air fry the chicken an additional 5 minutes at 375°F (190°C). Switch the position of the trays in the air fryer oven once more (again, don’t flip the chicken). Air fry for 3 minutes at 375°F (190°C). (That's 13 minutes of air frying time total.)
Half batch directions: If you only have schnitzel on the top rack, air fry for 7-8 minutes total at 375°F (190°C). No need to flip the chicken!
Use a meat thermometer to ensure the chicken has reached a safe minimum internal temperature of 165°F (74°C).
Serve the chicken schnitzel with the lemon wedges. Squeeze a bit of lemon juice on the chicken right before eating. Enjoy!