Serves 4 to 6 as a first course.
Fresh pasta is the best choice for this dish; supermarkets sell 9-ounce containers of fresh pasta in the refrigerator section. Be sure to use the entire 4½ quarts pasta cooking water called for—some of the boiling water is used to warm the serving bowls. When boiling the pasta, undercook it slightly (even shy of al dente) because the pasta cooks an additional minute or two in the sauce just before serving. Note that Fettuccine Alfredo must be served immediately; it does not hold or reheat well.
1 ½ cups heavy cream
2 tablespoons unsalted butter
1/4 teaspoon ground black pepper
9 ounces fresh fettuccine
1 ½ ounces Parmigiano-Reggiano, grated (about 3/4 cup)
1/8 teaspoon freshly grated nutmeg
1. Bring 1 cup of the heavy cream and the butter to a simmer in a 3- to 4-quart saucepan over medium heat; reduce the heat to low and simmer gently until the mixture reduces to 2/3 cup, 12 to 15 minutes. Off the heat, stir in the remaining ½ cup cream, ½ teaspoon salt, and pepper.
2. While the cream reduces, bring 4 quarts water to a rolling boil, covered, in a large stockpot or Dutch oven. Using a ladle or heatproof measuring cup, scoop about 1/2 cup boiling water into each serving bowl; set the bowls aside to warm. Add 1 tablespoon salt and the pasta to the pot of boiling water; cook the pasta until just shy of al dente. Reserve 1/4 cup pasta cooking water, then drain the pasta.
3. Meanwhile, return the cream mixture to a simmer over medium-high heat; reduce the heat to low and add the pasta, Parmesan, and nutmeg to the cream mixture. Cook over low heat, tossing the pasta with tongs to combine, until the cheese is melted, the sauce coats the pasta, and the pasta is just al dente, 1 to 2 minutes. Stir in the reserved pasta cooking water; the sauce may look rather thin but will gradually thicken as the pasta is served and eaten. Working quickly, empty the serving bowls of the water; divide the pasta among the bowls, tossing the pasta to coat well with the sauce. Serve immediately.