Get started: Remove all the packaging from the lamb and cut away the string. Unroll the meat and, using a sharp knife, make incisions lengthways into any thicker parts of the meat to even it out as much as possible. It should be about 5-6cm thick when finished. Pop the meat into a large roasting tin.

Peel and grate the garlic into a bowl. Tip in 1 tsp dried oregano and grate in the lemon zest. Sprinkle in a generous pinch of salt and pepper and stir in 1 tbsp olive oil. Rub the marinade all over the lamb and set aside for at least 30 mins, to allow the meat to come to room temperature.

Cooking indoors: Preheat your oven to 200°C/Fan 180°C/Gas 6. Pour 1 tbsp oil into a large, heavy frying pan and bring up to a high heat.

When the pan is smoking hot, add the lamb. Cook for 2 mins on each side, till well coloured. Transfer the lamb back to the roasting tin and slide into the hot oven. Cook for 25 mins for medium-rare, or another 10 mins for medium. Set the cooked lamb to one side and let rest for 20 mins before carving.

While the meat rests, pick and shred the mint leaves and slide them into a bowl. Stir in the yogurt and the juice from half of the lemon, along with a little salt and pepper. Serve with the sliced lamb and wedges of the remaining lemon.

Cooking outdoors: Light your barbecue and bring to a medium-high temperature. Add the lamb and cook over the hot coals for 2 mins on each side, till well browned. Use tongs to transfer the meat to a cooler part of the grill and cover with a lid. Continue to cook, turning occasionally, for 25 mins for medium-rare, or another 10 mins for medium. Set the cooked lamb to one side to rest for 20 mins before carving.

While the meat rests, pick and shred the mint leaves and slide them into a bowl. Stir in the yogurt and the juice from half of the lemon, along with a little seasoning. Serve with the sliced lamb and wedges of the remaining lemon.

Know your grill: When lighting your barbecue, lay the bulk of your coals to one side, gently sloping 3/4 of the way to the other side. This helps to regulate the heat, giving you fierce 'direct' heat to brown your meat over, and gently 'indirect' heat to slowly finish it off.

Get ahead: Prepare your lamb and slather with the oregano and garlic marinade the night before cooking, to give all that flavour time to really seep into the meat.

Next week in the Summer Roast Box: Homemade Hot Sauce Venison Haunch. A proper hot sauce is an essential part of any discerning bbq. Whip up this tangy number to spoon over slices of tender, smoky venison haunch.

For a showstopping bbq side dish, cut inch-thick slices of watermelon and pop onto the grill next to your meat. Cut the caramelised, charred fruit into chunks and toss with summer leaves before dressing with olive oil, fresh oregano and chilli.