One of the most popular outdoor summer meals from the barbecue is butterflied leg of lamb, nicely browned and crusty on the outside, pink and juicy in the middle.
Check the weight to determine cooking time. As a general guide cook at 200ºC 20 mins per 500g for rare, 25 mins per 500g for medium.
You’ll find a butterflied lamb leg has an uneven thickness, so the thinner parts will cook faster than the thicker parts, which naturally means some will be cooked a little more, some a little less. A good thing if you guests like varying doneness. Cooking to no more than a medium doneness will keep all of the meat juicy and not overcooked.
The flat boned leg can be roasted on a rack at a moderate or high temperature, or barbecued or grilled.
Suggested Flavourings
First marinate, season or flavour the lamb as you wish. Try the following:
A combination of rosemary or garlic oil, soy sauce, lemon juice, pepper and pomegranate molasses or spicy apricot sauce
Crushed garlic, grated fresh ginger, lemon rind and juice, teriyaki marinade or light soy sauce, pepper
Crushed garlic, ground coriander, cumin, pepper, olive oil, honey, lemon juice, sweet chilli sauce
Cooking the butterflied leg
To roast
Preheat the oven to 160ºC. Lightly score the inside of the thickest part of a 1.5kg butterflied lamb leg in a criss-cross fashion, giving the lamb a more overall thickness. Combine 2 tbsp each of chopped parsley and capers, the rind and juice of 1 lemon, and 1 tbsp olive oil, then rub over the lamb. Then season lamb with pepper and salt. Place in roasting dish, cover dish with baking paper and foil, roast for 2 hours, remove paper and foil and roast for a further 30 mins to brown lamb.
You can lightly score the inside of the thickest part of the butterflied lamb leg in a criss-cross fashion giving the lamb a more overall thickness if you’d like to cook it a little more evenly.
To barbeque
Preheat the barbeque to 200ºC (the burners should be set at medium).
Place the lamb in the centre of the barbeque, skin side up. Turn the burners directly under the lamb off. The remaining burners are left on to conduct and circulate the heat around the lamb.
Close the lid and cook for 25 minutes per 500g for a medium result. Test for doneness with tongs in the thickest part. Rare is soft when pressed, medium is springy and well done is very firm.
Remove lamb, cover loosely with foil, and rest lamb for 10-15 minutes before slicing.
A kettle barbeque is also a great way to barbecue lamb, cooking over coals adds amazing flavour. As a general rule heap about 25 heat beads in rails on each side of the barbecue. Once the beads have been lit it’s important to allow them to develop to a fine ash stage before adding the lamb. Cook as directed above.
To slow roast
Slow roasting is another option, cook in the oven at 140ºC for around 4 hours or a little faster at 160ºC for 2-3 hours. Whatever way you choose, use a roasting dish similar to the size of your roast. Cover the dish with baking paper and foil for the first half of the cooking time and then remove it so your lamb browns well. When it’s done the meat will be meltingly tender and fall from the bone.