Get a large frying pan over a high heat and a large saucepan filled with salted water on the boil. Cook your pasta according to the packet instructions while you do everything else.

In the pan fry the pancetta until browned and then add the leeks. Stir fry until softened, then add the water and mussels. Add a lid and cook for 4 minutes.

While the mussels steam, combine the cream, egg and parmesan. Season with plenty of black pepper. Remove the frying pan from the heat and add the cream mix and the pasta, stirring and tossing the whole time. Discard any mussels that have not opened up and serve in bowls with a sprinkling of parsley.