6 garlic cloves, peeled and finely chopped or crushed
Grated zest of 1 lemon, juice of 2 lemons
2 tablespoons rapeseed or olive oil
Method
In a small bowl, mix the marinade ingredients together.
On a chopping board make several slashes all over the lamb with a sharp knife. Rub the paste all over the lamb, pushing deep into the holes. Transfer to a large food bag, seal and marinate in the fridge for up to 2 hours, or overnight if time allows.
Preheat the oven to 160°C, 140°C Fan, Gas Mark 3.
Line a large roasting tin with foil then baking parchment. Scatter the potatoes over the roasting tin. Season the potatoes, add the sliced onion and the bay leaves.
Position the joint on top of the potatoes. Wrap in the parchment and extra foil. Roast for 4 hours until tender.
Remove the joint from the oven, increase the heat to 220°C, 200°C Fan, Gas Mark 7. Unwrap the foil and parchment, spoon any meat juices over the joint and continue to cook for a further 30 minutes.
Remove the roasting tin from the oven, wrap in foil and leave to rest for 30 minutes.
Slice the lamb and serve with a Greek salad and the remaining accompaniments.