Traditionally a leg of lamb bought from the High Street butchers or supermarket butchery counter or pre-packed section can be used in three ways. Those are: Leg left whole and cooked bone in. Leg divided into two giving you the choice of the fillet or the bonier shank end. Most legs of lamb sold nowadays have the aitch bone removed already. What the buggery is the 'aitch bone' ? I hear you politely ask.
The 'aitch' bone is half a hip bone and fiddly to cut around so the High Street butcher takes it out for ease of carving when cooked. In a supermarket the legs of lamb arrive with the 'aitch' bone removed so that the sharp edges don't accidentally pierce the cryovac packaging and spoil the meat by letting air in and thus reducing the time in which the meat needs to be sold by or in the worse case, going off. There you go. You can all impress your friends with this choice bit of butchery knowledge now. Wanna learn more? Read on.
I'm going to show you how, with a sharp paring or boning knife, you can create a nice carvery leg and have some lean lamb steaks for another time. You need a bit of butcher's string as well. Smile nicely at your local butcher and he or she might give you some for free.
Righty ho. First we have a full leg of lamb. There it is in the picture below. It has bones in it otherwise it would fall down in the field. There are only three bits of bone and cartilage to know and when you are cutting/trimming always cut away from yourself otherwise a mischief to one's self could be done.
This is a full leg of lamb. Don't be scared of it.
This is a marvellous picture I drew earlier. Be impressed.
What we are going to do is remove the top muscle (the lamb version of topside) by cutting along the leg bone from the visible end keeping the edge of the knife close to the bone. The knife journey is from right to left. Muscles have seams and once you see the slightly grayer skin (the seam) inside the leg you can actually push the muscle away and then cut through the skin to remove the lamb topside.
Put the lamb topside to one side as we'll come back to that in a bit. You are doing well, by the way. You now need to remove the big leg bone (the one that I've drawn, labelled as leg bone and looks a bit like a penis on the picture). The drawing accident wasn't deliberate btw. Right, concentrate.
To find the knee joint pick up the leg of lamb and bend it like you are flexing its knee. You should see a bit of movement. That's where the top end of the knee joint is and where you should start. Jab the space with the end of your knife and push the knife in. Then cut out the knee joint. It looks like a reversed D shape. The leg bone is easy peasy. With the tip of your knife tease the meat away from the bone along its length, then underneath gradually freeing the bone and always cutting away from you. Both bones removed? Well done.
Trim off any fatty or grisly bits from the surface and interior of the leg. They are obvious and creamy white. There is a bit of deep fat containing a grey-green lymph node that needs to be taken out too. Have a look at the photo above and it is there, smack in the middle of the leg. You are doing very well so far. Nobody has fainted or stabbed themselves yet. Good.
Get your butchers string and if you know how to tie a slip knot (butcher's knot) fab. Otherwise any tight knot will do. Just turn the leg of lamb skin up. Tidy round any loose bits of flesh and tie up with just two knots. Voila! A carvery leg!
Now come back to your lamb topside. Trim any fatty or grisly bits from the joint surface and you can either steak it for luscious leg lamb steaks or keep it whole (freeze it maybe) for a smaller boneless lamb joint another time. If you look at the photo above I have butterflied the last steak as it was at the smaller end of the lamb topside and didn't look as sexy as the other leg lamb steaks.