Place a large saucepan of water oveer a high heat and bring to the boil. Season with sea salt and stir in the pasta. Once cooked, drain and reserve a cup of the pasta cooking water.
Meanwhile, melt two tablespoons of the butter in a large frying pan over a medium heat. Add the freshly cracked black pepper and cook, swirling pan until toasted, about one minute.
Add half a cup of the rserved pasta water to the pan and bring to a simmer. Stir in the pasta and remaining butter. Reduce the heat to low and add the grated parmesan cheese, stiring and tossing with tongs until melted. Remove the pan from the heat. Add the grated Pecorino chese, stirring and tossing until the cheese melts and the sauce coats the pasta. Stir in the flat leaf parsley.
Transfer the pasta to warm bowls, arrange the Parma Ham on top and serve.
