Put all the ingredients except the lamb in a blender, and blend to a paste consistency.
Marinade the lamb shanks with the paste, overnight or at least a few hours,.
Turn oven on to 200 degrees C.
Place the lamb shanks in a baking tray with the marinade, pour the olive oil.
Cover the tray with foil all around 3 times so it is completely sealed. Be careful the foil does not tear, otherwise the meat will burn.
This is very important, because if it is not then the meat will burn..
Place in the oven for 25 minutes, and then turn the heat down to 160 and cook for a further 3 hours.
Take out of the oven and unfold the foil. Cook uncovered for a further half hour.