This is the classic, rich Roman pasta dish. Fresh pasta is the best choice, here. When boiling the pasta, undercook it slightly (even shy of al dente) because the pasta cooks an additional minute or two in the sauce. Note that Fettuccine Alfredo must be served immediately; it does not hold or reheat well.
1-1/2 cups heavy cream
2 tablespoons unsalted butter
1/2 teaspoon ground black pepper
9 ounces fresh fettuccine
1-1/2 ounces Parmesan cheese, grated (about 3/4 cup)
(Additions: 2 T. finely chopped shallots & 2 cloves minced garlic, sautéed)
a small pinch freshly grated nutmeg
2 tablespoons finely minced parsley
Bring 4 1/2 quarts water to rolling boil, covered, in large stockpot or Dutch oven. Using ladle or heatproof measuring cup, fill each individual serving bowl with about 1/2 cup boiling water; set bowls aside to warm.
While water comes to boil, bring 1 cup heavy cream and butter to simmer in 3- to 4-quart saucepan over medium heat; reduce heat to low and simmer gently until mixture reduces to 2/3 cup, 12 to 15 minutes. Off heat, stir in remaining 1/2 cup cream, 1/2 teaspoon salt, and pepper.
Add 1 tablespoon salt and pasta to boiling water; cook pasta until just shy of al dente. Reserve 1/4 cup pasta cooking water, then drain pasta.
Meanwhile, return cream mixture to simmer over medium-high heat; reduce heat to low and add pasta, Parmesan, (sautéed shallots and garlic, if using) and nutmeg to cream mixture. Cook over low heat, tossing pasta with tongs to combine, until sauce coats pasta and pasta is just al dente and cheese is melted, 1 to 2 minutes. Stir in reserved pasta cooking water; sauce may look rather thin but will gradually thicken as pasta is served and eaten.
Working quickly, empty serving bowls of water; divide pasta among bowls, tossing pasta to coat well with sauce. Sprinkle with the minced parsley and serve immediately.
Note: I sometimes add some fresh spring peas, or tender young asparagus tips. I’ve also added prawns or bacon to change the flavor profile.