Place cucumber in a mini food processor or grate with a box cheese grater. Drain the liquid from the cucumber in a metal strainer and use the back of a spoon to help squeeze out any excess liquid.

Combine grated cucumber with Greek yogurt, garlic, lemon juice, mint, dill, salt, and pepper. Refrigerate until ready to serve.

Season fish with 0.5 teaspoon salt. Cut into 8 strips.

Place flour on a plate and beat the egg in a shallow bowl. Combine panko with remaining salt, garlic powder, and oregano on another plate.

Preheat the air fryer to 400F. Coat fish in flour, dip into egg, then into panko mixture. Spray both sides with oil and air fry for 4 minutes, turn and cook another 2-3 minutes until golden and crispy.

Sear or bake fish in oven at 425F for 5-6 minutes per side until golden.

Assemble tacos by placing 1/4 cup cabbage on each tortilla, top with a piece of fish, tzatziki sauce, tomatoes, red onion, and fresh lemon juice.