1. Remove lamb from the refrigerator 1 hour before roasting to bring it nearer to room temperature.
2. Trim and remove any silvery connective tissue but leave the fat cap in place. If there is an excessive layer of fat on top, you can slice some of the top layer off.
3. Preheat the oven to 220°C with a deep shelf in the centre.
4. Prepare a wet rub: 3 minced garlic cloves, 1 Tbsp Dijon mustard, 1 Tbsp olive oil, 1 Tbsp chopped fresh rosemary, 1 Tbsp of lemon zest. Mix together and put aside until the meat is at room temperature.
5. Cut 2 whole garlic in half and place these cut side up in the roasting pan with a few sprigs of fresh rosemary.
6. Pat lamb dry, with a paper towel, then use a sharp knife to make shallow cuts all over. Use a pastry brush to spread the rub mixture over the surface and place lamb on the cut garlic and rosemary sprigs in the roasting pan.
7. Roast lamb for 20 minutes, fat side up, then reduce the temperature to 180°C fan forced. Roast for a further 2 hours before checking the internal temperature with a meat thermometer (see temperature chart below).
8. Once the meat is cooked to your liking, remove and transfer to a warm plate, cover with a foil tent and rest lamb for 30 minutes.

To serve

Once rested, take a sharp carving knife and carve the lamb off the bone, in the direction of the grain.

What should I serve with the roast lamb?

Classic roast meal with roasted vegetables like carrot, parsnip, roast potato. And don't forget the mint sauce and gravy!

If you want something a bit different, lamb is perfectly suited to more Mediterranean flavours. Add a dollop of tzatziki and hummus, with a side of boiled baby potatoes. 

You can also serve lamb with a lighter side, like a couscous salad with roasted beetroot. 

What size lamb leg should I get? 

The bone-in weight guide:

• 2–2.4 kg - 6–8 people 
• 3.5–4 kg - 6–10 people 

Cooking time for roast lamb

For medium done, follow these guides.

• 1.5kg - 1 hour 40 minutes
• 2kg  - 2 hours 5 minutes
• 2.25kg -  2 hours 30 minutes
• 2.5kg -  2 hours 50 minutes
• 2.75kg -  3 hours

Internal temperature

Use a thermometer to take away the guess work!

• Rare lamb - 50°C
• Medium rare lamb - 55°C
• Medium lamb - 60°C
• Well done lamb - 70°C
• Fall apart tender lamb - 80°C