Preheat the oven to 160C/320F/gas 3.
Heat the oil in the frying pan over a high heat.
Add the lamb shanks and fry, turning occasionally, until golden-brown on all sides.
Transfer the lamb shanks to the casserole, and add the barley, stock and herbs. Bring up to the boil and immediately take off the heat.
Cover with the lid and cook in the oven for one and a half hours.
Remove the casserole from the oven, add the vegetables and a little more water if needed.
Season to taste with freshly ground black pepper and return it to the oven for another hour.
Remove the casserole from the oven and check that the lamb is tender and falling off the bone. If you think that it's not quite ready, return it to the oven for another 15 minutes and check again.
Transfer the lamb shanks to a chopping board and take the meat off the bones. Return the meat to the casserole.
Place the casserole on the hob and heat to a simmer.
Add the blanched parsley leaves and season to taste, with salt and freshly ground black pepper.
Serve immediately.
