Melt the butter in a medium saucepan. Add the flour, stirring constantly, until blended. Remove from the heat and add the cream and stock. Return to the stove and bring to a boil while continuing to stir. Add the sherry, salt, pepper and nutmeg, and stir until well blended.
Gently stir in the Smoked Salmon. Arrange the cooked pasta on four warmed dinner plates. Divide the sauce among the plates, ladling it over the pasta. Garnish with a sprinkle of chopped parsley.