Prepare the lamb
Take the lamb out of the fridge around 2 hours before cooking to come up to room temperature. Preheat the oven to 220°C/200°C fan/gas 7. Make small slits across the surface, tuck in slivers of garlic and sprigs of rosemary, then rub with olive oil and season generously with sea salt and freshly ground black pepper.
Roast with confidence
Choose a sturdy roasting tin that's large enough to hold the joint comfortably. Sit the lamb on a trivet or a bed of onions and carrots, adding whole garlic cloves, lemon wedges and herbs if you're making gravy from the roasting juices. Pour 250ml of water or white wine into the base of the tin.
Roast for 20 minutes, then reduce the oven to 180°C/160°C fan/gas 4. Cook for 40 minutes per kg for rare, 50 minutes per kg for medium, or 60 minutes per kg for well done.
We have plenty of roast lamb recipes that are perfect for Christmas Day, including our traditional roast lamb recipe with mint sauce and lamb kleftiko for a Greek twist.
Rest and serve
Transfer the lamb to a carving board and cover loosely with foil. Leave it to rest for around 45 minutes while you finish the gravy and side dishes. Resting allows the juices to settle, giving you beautifully tender slices ready to serve.