Pre-heat a lightly oiled barbecue or chargrill pan over medium high heat.
Combine garlic, soy, sesame oil and mirin in a small bowl.
Rub marinade over lamb and season.
Cook lamb, brushing with marinade, for 12 to 15 minutes on each side or until cooked.
Set aside to rest for 10 minutes and thinly slice.
Meanwhile, preheat oven to 200°C (180° fan-forced).
In a large roasting pan lined with baking paper, place the pumpkin, potatoes, cauliflower and broccoli.
Drizzle with the olive oil, and sprinkle with the spices.
Season and toss to coat.
Roast vegetable for 30 to 35 minutes, turning once, or until golden and tender.
Add spinach to the pan, toss and sprinkle with hazelnuts.
Serve lamb with roasted vegetables.
A butterflied leg of lamb is prepared from a boneless leg and it cooks faster and more evenly.
Just ask the butcher to do it for you when buying the leg of lamb.
If you can’t find a butterflied leg try using a butterflied shoulder or a boned and rolled shoulder.
Perfect for the barbecue or grill, the increased surface area of this cut makes it much quicker to cook than the whole leg.