Combine the marinade ingredients in a bowl. Place the meat in a shallow dish and pour the marinade over it. Leave to marinate for at least 5-10 minutes.
Mix all the salad ingredients together. Taste and season with salt and black pepper. Set aside while you cook the steak.
Heat a pan or barbecue. When it is really hot add the steak and allow to cook for 4-5 minutes before turning and cooking for another 4-5 minutes depending on how you like your steak cooked. A 2.5cm thick steak will be medium rare at this point. Allow to rest for a couple of minutes.
Heat the tortilla wraps as per packed instructions. When the steak has rested cut into thin strips and serve piled onto the wraps along with the leaves, salad and a spoonful of crème fraîche. Sprinkle over the reserved green chilli.