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 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 beaten egg in a shallow bowl. In another plate, combine panko with remaining salt, garlic powder, and oregano.

Preheat oven to 425F. Coat fish strips in flour, dip in egg, then in panko mixture. Place on parchment-lined baking sheet, spray with oil, and bake for 5-6 minutes, turn and bake another 5-6 minutes until golden.

Assemble tacos: Place 1/4 cup cabbage on each tortilla, top with a fish strip, tzatziki sauce, diced tomato, red onion, and a squeeze of lemon.