Prep the fish: Pat the fillets dry with paper towels. This helps the coating stick and prevents steaming. If any fillets are very thick, cut them into uniform sizes for even cooking.
Season the fish: Sprinkle both sides with salt and pepper.
Add a light dusting of paprika if you want extra color.
Set up your dredging stations: In one shallow bowl, whisk 1/2 cup flour with 2 tablespoons cornstarch, 1 teaspoon garlic powder, 1/2 teaspoon onion powder, 1 teaspoon paprika, 1 teaspoon salt, and 1/2 teaspoon black pepper. In a second bowl, beat 2 eggs with 1 tablespoon water and a pinch of salt. In a third bowl, add 1 to 1.5 cups panko.
Stir in 1 teaspoon lemon zest if you like.
Coat the fish: Working one piece at a time, dredge the fish in the seasoned flour, shaking off excess. Dip into the egg, letting extra drip off. Press into the panko until fully coated. Press gently to help the crumbs stick.
Preheat the air fryer: Heat to 400°F (200°C) for 3–5 minutes.
A hot basket helps the bottom crisp.
Oil the basket and the fish: Lightly spray the air fryer basket. Place fillets in a single layer with space between them. Lightly spray the tops of the fillets until the crumbs look just moistened—not soaked.
Air fry: Cook at 400°F for 5–6 minutes.
Flip gently with tongs, spray again, and cook another 4–6 minutes. The fish is done when it flakes easily and the coating is golden brown. Target internal temp: 145°F (63°C).
Finish and serve: Squeeze fresh lemon over the top, sprinkle with parsley, and serve hot. Tartar sauce, hot sauce, or a simple garlic-lemon yogurt sauce all work well.