1Preheat the air fryer to 188°C (370°F).
2Remove the steaks from the refrigerator and place them on a cutting board.
3In a small bowl, mix the flour, garlic powder, paprika, salt, and pepper.
4In another bowl, beat the egg with water until well combined.
5Coat each steak in the flour mixture, then dip in the egg mixture, and coat again in the flour mixture for a double crust.
6Place the steaks in a single layer in the air fryer basket.
7Cook for 12-15 minutes, turning halfway and spraying with a little oil for even browning.
8While the steaks cook, prepare the sauce: melt the butter in a small saucepan over medium heat. Gradually whisk in the flour, then the milk, salt, and pepper. Stir until the sauce thickens, then remove from heat.
9Remove the schnitzels from the air fryer and pour the warm sauce over them before serving.