Peel and crush the half head of garlic, and rub the meat all over with olive oil.

Sprinkle the cinnamon, oregano and salt all over the lamb, then top with the crushed garlic and the juice of one lemon, and rub in using your hands (wash and rub your hands with the cut lemon to help get rid of the smell of garlic afterwards).

Cover and chill for eight to 12 hours.

Shortly before cooking, heat the oven to 160C (140C fan)/325F/gas 3.

While it’s heating up, prepare the vegetables.

Waxy potatoes (such as charlottes, maris peers, anyas or anything described as a salad variety) are the best bet here, because they will keep their shape during the long cooking time.

There’s no need to peel them unless they’re very dirty.

Cut the potatoes into wedges (if they’re small, just cut them in half; leave them whole if they’re real babies).

Peel the onion (a yellow onion would also be fine here, as would shallots, peeled and cut in half), then cut it into chunky wedges.

Halve the pepper, remove and discard the stalk, pith and seeds, then cut the flesh into thick strips.

Wash the tomatoes – if you prefer, use larger ones, in which case cut them in half or, for really large fruit, into wedges.

You could also add big chunks of feta (don’t crumble it, otherwise it will dissolve into the gravy) or kefalotyri, a few sprigs of fresh oregano, fennel, or even chunks of courgette or aubergine, though those aren’t strictly traditional.

Take a large lidded casserole dish that’s big enough to hold the lamb with the lid on tightly, or use a roasting tin lined with enough baking paper to fold over the top of the joint on both sides (you’ll probably need at least two sheets of paper set at right angles to each other).

Put the potatoes, onions, pepper and tomatoes in the casserole or tray.

Lay the marinated lamb on top of the vegetables, then pour any remaining marinade over the top.

Cut the remaining head of garlic and lemon in half across their thickest points, squeeze the lemon briefly on top of the lamb (no need to wring it absolutely dry), then tuck the lemon shells, the half garlic heads and the bay leaves in and around the joint.

Pour 200ml water into the dish.

If using a casserole dish, tuck a damp piece of greaseproof paper on top of the meat, then cover with the lid; if using a roasting tray, sprinkle the overhanging paper with water, then fold it up and over the meat and tuck in to form a sealed package.

Bake for four to five hours, until the meat is very tender.

When the lamb is soft, turn up the oven to 220C (200C fan)/425F/gas 6 and remove the lid and/or greaseproof paper.

Roast for a further 10-15 minutes, then lift out the meat and set aside to rest for about 30 minutes.

Put the pan of vegetables back in the oven for 15 minutes, until they’re starting to brown, keep warm until the meat has finished resting, then carve and serve up.