Open out the ham and place in a roasting dish. Season with wine, lemon juice, salt and pepper. Let rest 20 minutes. Meanwhile, preheat oven to 250 degrees C.
In the ham, place layers of prosciutto, sausage and mozzarella. Top with diced green olives, parsley and carrot. Roll up the ham again and tie with several loops of kitchen string.
Wash the potatoes but leave the skins on. Thickly slice and arrange around the ham in the roasting dish. Bake until golden brown, about 45 minutes.