Bring a large pot of cold water to a boil over high heat and salt it generously. Add the pasta and boil, stirring occasionally, until al dente, about 12 minutes. Drain pasta in a colander, leaving 3 to 4 tablespoons pasta water in the bottom of the pot.
Return pot to a low heat. Whisk the butter in bit by bit, letting each piece melt completely before adding the next, to make a creamy sauce. Toss the pasta in the sauce. Season with salt and pepper and nutmeg if desired. (Add a little warm water if the pasta looks shiny.) Transfer to warmed bowls and serve warm, with Parmesan sprinkled over each dish if desired.
Copyright 2005 Television Food Network, G.P. All rights reserved
From Food Network Kitchens