You may own recipe books describing lamb shanks as underrated cuts of meat, perfect for cooks on a budget. Those books were written before 1990, when shanks started appearing on fashionable tables. Still, they remain cheaper than leg; and they are particularly succulent.
They may be slow-roasted, like a shoulder (see here, or here). Or, because the meat is so crammed with connective tissue and fat, they may be braised -- a process that dries out leaner meats.
I assume here that you have small shanks, each a serving for one person. But they are often larger than that.
2 onions, chopped
1 carrot, chopped
1 stick celery, chopped
1 bay leaf, 1 sprig rosemary
1 head garlic, separated into cloves
4 lamb shanks
In a casserole large enough to contain the shanks, soften the onion, carrot and celery in about 2 tbsp olive oil, adding a little more oil if the vegetables start to catch.
Meanwhile, in a frying pan, heat some groundnut or sunflower oil (which takes a higher heat than olive oil) over a medium flame, and brown the shanks all over. You'll probably need to do it two at a time.
When the vegetables are golden, lay the browned shanks on top, and throw in the garlic cloves, bay leaf and rosemary. Grind over some salt. (I prefer to add pepper at the table -- it can go bitter if stewed for a long time.)
Cover the pot, and put it into a gas mark 1/140 C oven. Check after an hour; if the braise is starting to simmer, you can turn down the heat to 130 C, or lower if your oven will go lower than that (mine won't). Simmer, very gently, for a further two hours, turning the shanks from time to time.
Lift the shanks from the liquid (the meat and vegetables in my casserole at the weekend had thrown off about a litre of it) on to a plate. Strain the liquid through a sieve into a bowl. Return the shanks to the casserole, cover, and put it back into the bottom of the oven.
If you have a glass bowl, you can see the substantial layer of fat on top of the liquid. Spoon it -- the fat -- off (not into the sink, because it will solidify); when the layer of fat is too thin to spoon off accurately, you can dab at it with paper towels.
You can discard the vegetables, with the exception of the garlic, from the sieve -- they have given up their flavour. Squeeze the garlic from the hulls into the sauce. Pour the sauce into a saucepan, and simmer it to reduce it to the thickness and flavour you like. Remember that the salt in it will concentrate, so keep tasting.
Serve the shanks in a dish, carving off the meat at the table; serve the sauce in a jug.