Pulse the fish in a food processor until finely minced. Transfer to a bowl.
Blend the parsley, cilantro, pepper, onion, and garlic until finely chopped. Strain well, squeezing out as much liquid as possible.
Mix the vegetables with the fish, olive oil, and spices.
Spread onto a greased sheet pan, about ½-inch thick. Score into rectangles. Place the wire rack on top, add the vegetables, drizzle with oil, and season lightly with flaky salt.
Bake at 400°F for 30 minutes, then broil for 3–5 minutes if desired.
Meanwhile, mix together all the tzatziki ingredients.
Warm the pita, fill with the fish kebabs, chopped roasted vegetables, and tzatziki. Enjoy!
