Step 1
Preheat oven to 150°C (130°C fan-forced). In a small bowl, mix the garlic powder, onion powder, oregano and paprika with 1 tbs sea salt flakes and 1 tbs freshly ground black pepper. Rub the lamb with the oil and sprinkle all over with spice mixture. Place lamb, fat-side up, in a 33cm x 23cm roasting pan. Pour the stock and sprinkle the garlic cloves around the lamb in the pan.
Step 2
Cover the lamb tightly with foil. Cook for 4 hours or until tender. Increase oven temperature to 200°C (180°C fan-forced). Uncover the lamb and roast, basting with pan juices occasionally, for 30 mins or until the top of the lamb is caramelised and crisp. Carefully transfer lamb to a large serving platter. Cover loosely with foil and set aside for 15 mins to rest.
Step 3
Strain cooking liquid from the roasting pan into a large jug. Allow fat to rise to the top. Using a spoon, skim and discard as much fat as possible from the cooking liquid. Transfer the cooking liquid to a small saucepan and bring to the boil over high heat. Cook until liquid is reduced by half. Remove from heat and stir in the dill, mint and parsley. Set aside for 2 mins to cool slightly. Whisk in the yoghurt. Season with salt and pepper.
Step 4
Meanwhile, to make the zucchini-fetta fritters, in a medium bowl, toss the zucchini with 1 tsp salt. Set aside for 10 mins. Transfer zucchini to the centre of a clean tea towel. Gather the corners of the tea towel together to enclose, then use your hands to squeeze excess moisture from zucchini. Return zucchini to the bowl.
Step 5
Add the fetta, spring onions, dill, mint, parsley, egg, breadcrumbs, cornflour, 3/4 tsp salt and 1/2 tsp freshly ground black pepper to the zucchini, then stir until well combined. Divide the mixture into 16 even portions.
Step 6
Heat 2 tbs of olive oil in a large, heavy-based frying pan over medium heat. Place 8 portions of zucchini mixture in the pan and flatten slightly. Cook, turning once, for 3-4 mins each side or until fritters are golden brown and crispy. Transfer to a large plate lined with paper towel. Season with salt and pepper. Cover to keep warm. Repeat with the remaining oil and remaining portions of zucchini mixture.
Step 7
Drizzle half the yoghurt mixture over the lamb. Thickly slice the lamb and serve with the fritters and remaining yoghurt mixture.