Heat the oil in a large frying pan, and sauté the onion and garlic for 5 minutes until soft. Add the lamb and ½ of the dried herbs, and stir-fry for 2 minutes, until warmed through.
Meanwhile, lay the tortillas out onto plates. Divide the salad between the wraps, chopping the tomatoes and cucumber into smaller pieces as you go, and top with the lamb mixture. Sprinkle the remaining dried herbs over the tzatziki and serve on the side.