Melt butter in a small saucepan over a low heat. Off the heat add the cream and the grated parmesan. Put back on the fire to heat the sauce through and melt the cheese. Do not boil. Stir in the salt and pepper. Cook the fettuccine in plenty of boiling salted water. Drain well. Combine the noodles and the sauce and leave to stand covered for two minutes before serving.