Combine cucumber, yoghurt, oregano and garlic together, season with salt and pepper. (to save time you can make the Tzaziki the day before and keep it in the fridge)
To make the greek wrap
Heat a non stick frypan to high heat. Seal the lamb on all sides until golden brown and transfer to a plate to rest.
Lay the lettuce on the wrap, then slice the rested lamb into thin slices, and place on top of lettuce, before adding the sliced tomato, avocado, red onion, chopped mint.
Dollop some tzatziki over the filling, and finish it all off with a zesty squeeze of lemon before closing the wrap and tucking in!