1.Preheat the oven to 200°C (180°C fan-forced).
2.Heat one tablespoon of the oil in a large, flameproof baking dish; add lamb, cook until browned all over. Sprinkle lamb with salt and freshly ground black pepper. Add potatoes, lemon and garlic to pan and drizzle with remaining oil. Roast for 40 minutes or until lamb is cooked as desired. Remove lamb from baking dish; cover with foil; stand for 15 minutes.
3.Meanwhile, add zucchini and carrots to the potatoes in the dish and toss to combine. Increase the oven temperature to its hottest setting; roast the potato mixture for about 20 minutes or until tender and golden brown. Add the lemon thyme leaves to the vegetables in the baking dish and toss to combine.
4.Serve the lamb with the roasted vegetables and lemon.
The neck-end lamb racks are a cheaper alternative to the traditional racks of lamb.Note