Mix together flour, 1/4 teaspoon salt, and pepper in a shallow dish. Whisk together eggs and water in another shallow dish. Stir together panko and oil in a third shallow dish. Add desired seasoning to either panko and/or flour mixture.

Sprinkle vegetables with remaining 1/4 teaspoon salt. Dip in flour mixture, then in egg mixture, and finally in panko mixture to coat.

Preheat the air fryer to 400 degrees F (200 degrees C) and the oven to 200 degrees F (95 degrees C).

Arrange half of the vegetables in a single layer in the air fryer basket. Cook until golden brown, about 10 minutes. Sprinkle with additional salt, if desired. Transfer vegetables to oven to keep warm. Repeat with remaining vegetables.