To prepare the lamb, using a sharp knife, make three small incisions in each of the lamb shanks.
Secure together a piece of garlic and rosemary by wrapping an anchovy third around them and insert this into one of the incisions in the lamb, pushing in firmly. Repeat to use up all the garlic, rosemary and anchovy.
To cook the lamb shanks, heat a frying pan until hot and add one tablespoon of the olive oil to the pan. Add the lamb shanks and fry on each side for one minute until browned all over.
Meanwhile, heat a large ovenproof casserole dish until hot and add the remaining olive oil, shallots and garlic.
Fry the shallots and garlic for about 2-3 minutes, until just softened, but not browned.
Add the red wine and bring to the boil.
Add the canned tomatoes, fresh tomatoes, rosemary, thyme, butter beans and red wine vinegar and return to the boil.
Place the lamb shanks into the sauce and cover with the beef stock. Season with salt and freshly ground black pepper.
Bring to a simmer, cover and place in the oven to cook for 3-4 hours, or until the meat is meltingly tender and falling off the bone.
For the olive oil mash, place the potatoes into a large saucepan and cover with water. Add a pinch of salt, place on the heat and bring to the boil.
Simmer for 10-15 minutes until tender.
Drain well and return to the pan over a low heat for a few seconds to remove any excess moisture.
Using a potato masher or ricer, mash well, adding the olive oil to slacken and flavour the potatoes. Season with salt and freshly ground black pepper.
To serve, remove the lamb shanks from the sauce and place onto four serving plates.
Whisk the butter into the sauce and stir in the flatleaf parsley.
Taste to check the seasoning and add a little more salt and freshly ground black pepper if necessary.
Spoon the sauce over the lamb shanks and serve with the olive oil mash. Drizzle over a little extra olive oil to finish.