Mix all the ingredients in a bowl, and then add the lamb shanks. Leave in the fridge for a minimum 12 hours or preferably over night, as this helps to flavour and tenderize the meat.
Place the marinated lamb shanks in an oven tray. Pour ½ pint of cold water in the bottom of the tray. Cover the tray with foil, and place in a pre heated oven 160C/320F/Gas mark 3 for 2 ½ - 3 hours. Remove the Foil for the last hour, to add the vegetables.
Check every hour to insure it is not dried out and if it is, add a little more water. The lamb should be tender and ready to fall of the bone.
While the lamb is cooking, prepare the roasted root vegetables. Tumble all the ingredients in a large bowl. Place the vegetables in the roasted trays with the lamb for the last hour until cooked.
Remove cooked Lamb shanks and vegetables from the tray and place on a plate, cover and leave to rest in the warm oven.
Place roasting tray over a low heat and add the lamb stock, red currant jelly and crushed garlic. Reduce by ½ and strain into a clean pan and season to taste.
Evenly place the roasted vegetable in the centre of each plate. Place each lamb shank on top of the vegetables a carefully pour the finished sauce over the lamb.