1To make the marinade, put all the ingredients in a small food processor and process until the onion is finely chopped and the ingredients are well combined.
2To make the slow cooked lamb, put the lamb on a large plate. Rub the marinade all over the lamb. Cover and refrigerate for at least 2 hours.
3Insert the wire rack into the bottom shelf position. Preheat the oven. Select SLOW COOK/CONVECTION/HIGH/4 hours and press start.
4Heat the oil in a 4 ½ qt Dutch oven over medium-high heat. Remove the excess marinade from the lamb, reserving the marinade. Add the lamb and cook, turning, for 10 minutes, until browned all over. Transfer the lamb to a plate and set aside.
5Add the marinade from the lamb and the carrots to the Dutch oven. Cook, stirring, for 5 minutes until the vegetables start to soften. Add the stock. Gently scrape the bottom of pan with a wooden spoon to loosen any browned bits. Add the dates. Return the lamb and any accumulated juices to the Dutch oven. Cover with a tight-fitting lid or double layer of foil, pressed down around the edges to seal.
6Once preheated, put the lamb in the oven and cook for 4 hours. The lamb should start to fall apart when you pull it with a fork.
7Transfer the lamb to a tray. Using two forks shred the lamb and put in a serving bowl.
8Strain the cooking liquid into a small pitcher and pour a little over the shredded lamb.
9Place the lettuce leaves on a platter. Top with sliced tomato, avocado and lamb. Sprinkle with sesame seeds and serve.
Tip: Before you start cooking check that the Dutch oven fits in the oven.