||Pre-heat the oven to 160°C/140°C.
||Slice the unpeeled potatoes finely. Arrange them in layers in a deep-sided roasting dish.
||For the marinade, in a bowl, add anchovies, garlic, mint leaves, pepper, salt and olive oil. Mash them well together and set aside.
||Next, drizzle lamb with olive oil and place it on top of the potato slices. Spread the marinade over the entire surface of the lamb and add water.
||Cover with a couple of sheets of foil, ensuring you seal it extremely well.
||Roast in the oven for 5 hours.
||Remove the dish from the oven. Take off the foil and baste the lamb with some of the juices from the roasting dish. Put everything back into the oven for an additional 30 minutes.
||Finally, remove lamb from the oven, transfer it to a plate, cover with foil and leave it to rest.
||Serve immediately after resting the dish for 5-6 minutes.