I prefer hill lamb. It's healthily raised and its flavour is sweet and tender. It's easiest for me to buy Scottish lamb, but choose local lamb wherever you can. Welsh hill lamb is particularly good. I really enjoy spring lamb that comes onto the market from May onwards. We are lucky up here because Shetland 'spring' lamb doesn't appear until August or September. Their Northerly latitude results in later lambing, so good young lamb is in theory available longer.
Prepare the joint by rubbing it all over with Maldon salt and a smear of extra virgin olive oil. Make half a dozen sharp incisions in the joint and push a little sliver of new garlic and a sprig of fresh rosemary into each. Fine pieces of anchovy can be pushed into the flesh as well. If used sparingly it will enhance the delicate flavour of the the lamb.
Calculate the whole cooking time on an average of 16 minutes per 500g for medium. Seal the joint first in a hot oven at 230°C (450°F or Gas 8) for 15 minutes before reducing the temperature to medium - 200°C (400°F or Gas 6). As with all cooking times, use these simply as a guide. Keep an eye on the lamb and test it 25 minutes or so before you expect it to be ready. I like lamb fairly pink. Remember that if the juices run completely clear the lamb will be well done. Best to take it out of the oven before this. As with beef, cover it in tin foil and let it rest for 20 minutes or so in a warm place before carving.
Because the bone runs through the lamb it can be a bit tricky to carve. Use a sharp knife and start on the fleshiest side, cutting down towards the bone. Hold the lamb by the ankle and move it round, cutting methodically and logically.
