5-9 hours cooking time
What you need:
Put the yoghurt, lemon juice, garlic, oregano, salt and pepper into the slow cooker and stir. Add the beef to the mixture and turn to coat it in the mixture. Cover and cook for 5 hours (on a low setting) or 9 hours (on a high setting), until the beef is tender.
Shred the beef and mix it with the cooking juices.
To make the sauce, put the yoghurt, salt, lemon juice and mint in a bowl and mix well. Place the cucumber on kitchen roll and sprinkle with some salt. Using the kitchen roll squeeze the juice out of the cucumber and then add it to the sauce mixture.
Serve the shredded beef on a flat bread, drizzled with the sauce and topped with the lettuce and tomato wedges.