Lamb shanks are not a grill cut. They are hard-working muscle on the bone, and they turn into a proper dinner only after a long, wet cook. Lamb Shanks X2 is a pair, which is two plates or a very generous share. You will find them in lamb shanks and they belong in the same shop as other long cooks in slow cooker meat.
Oven shanks
Season, brown the shanks in a little oil in a casserole, 3 to 4 minutes a side, then lift them out. Soften an onion, a carrot and a stick of celery in the same pot, add a spoon of tomato puree, a glass of red wine or stock, and enough liquid to come halfway up the meat. Tuck the shanks back in, lid on, 160°C for 2 hours 30 minutes to 3 hours. They are done when a fork slides in and the meat wants to leave the bone, not when a clock says so. If the sauce is thin, lift the shanks out and boil the liquor on the hob for 5 minutes. Rest 10 minutes in the sauce so they do not dry on the plate.
Slow cooker and make-ahead
Same brown, then low for 7 to 8 hours or high for 4 to 5. Do not skip the brown; grey boiled lamb is why people think shanks are dusty. You can cook them the day before, chill in the sauce, lift the fat off the top, and reheat at 160°C for 30 minutes. They are better on day two. Shoulder chunks from lamb shoulder are the stew alternative if you want the same flavour without the bone-in presentation: 1kg Hogget Lamb Bone-in Shoulder Chunks for a casserole that feeds more people per pound.
What not to do
Do not try to pan-fry a shank like a steak. Do not blast it at 200°C uncovered. And do not confuse a shank with a chop from lamb chops; chops are 8 minutes, shanks are an afternoon. Serve on mash, polenta, or barley, with the sauce spooned over. A pair of shanks plus a cheap starch is a better dinner than a small dry roast rushed on a timer.
One pair of shanks is two dinners, not a party. If you need to feed six, cook two packs or switch to shoulder chunks and stretch the sauce with extra stock and a tin of tomatoes. Mash, not roast potatoes, is the better partner; you want something to catch the liquor.
Brown, lid on, wait until it yields. That is the whole craft of a lamb shank.