Steak: Season the steak generously with 1 tsp salt. Heat 1 tsp olive oil in a pan over high heat and sear for 2–3 minutes per side for medium-rare. Rest, then slice thinly.
Vegetables: Shred 1/8 cabbage, 1 small red onion and add to a bowl. Slice 1/2 cucumber into thin matchsticks and add to the bowl.
Sauce: In a small bowl, whisk together 1 tbsp mayonnaise, 1 tsp lemon juice, 1 tsp sugar and 1 tsp mixed herbs for the dressing. You can either toss the vegetables in the sauce or keep separate, and splat the sauce on the wrap instead.
Finish off: Warm the 2 flatbreads. Layer with sliced steak and slaw, then drizzle with the yoghurt dressing. Serve open or folded.