Preheat the oven to 220C, fan-forced (see Cooking tip). Thinly slice half the cucumber, then coarsely grate the remaining cucumber. Cut the tomato into thin wedges. Thinly slice the onion with a sharp knife or mandoline.
Step 2 — Make pickled onion
Combine 1 tsp red wine vinegar and ½ tsp sugar in a large bowl. Add the onion, season with salt and toss to combine. Set aside to pickle, tossing occasionally, until needed.
Step 3 — Warm tortillas
Enclose the tortillas in foil. Put in the oven for 8 mins or until softened and warmed through. Meanwhile, put the grated cucumber, ½ tsp Turkish seasoning and 2 tbs mayonnaise in a bowl and stir to combine. Taste, then season with salt and pepper.
Step 4 — Cook fish
Put the fish and 1 tbs olive oil in a bowl, season with salt and pepper and turn to coat. Heat a medium frypan over medium heat. Cook the fish for 3½-4 mins each side until browned and cooked through (see Kitchen 101). Remove the pan from the heat. Add the remaining Turkish seasoning and 1 tbs water to the fish and turn to coat.
Step 5 — Serve up
Flake the fish into chunks. Divide the tortillas among plates. Spread with the mayo mixture, then fill with the fish, tomato, drained pickled onion and sliced cucumber. Roll up to enclose the filling and enjoy!
Step 6 — Kitchen 101
Not sure if your fish is cooked through? Simply use a fork or the tip of a knife to take a peek inside the thickest part of the flesh; if it comes apart easily, the fish is cooked.