Add 12 oz dried fettuccine and cook according to package instructions until just al dente (usually 8–10 minutes). Stir occasionally to prevent sticking.

Before draining, reserve 1/2 cup of the starchy pasta cooking water. Drain the pasta and set aside; do not rinse.

Sauce

While the pasta cooks, grate 1 1/2 cups Parmigiano-Reggiano and set aside in a bowl so it’s ready to add to the sauce.

In a large sauté pan or shallow skillet over medium-low heat, melt 6 tablespoons unsalted butter. Add 1 teaspoon minced garlic and cook, stirring, just until fragrant—about 30 seconds. Do not brown the garlic.

Pour in 1 1/2 cups heavy cream and increase heat to medium. Warm the cream until it begins to steam and small bubbles form at the edge, about 2–3 minutes. Do not boil vigorously.

Reduce heat to low. Stir in 1 1/2 cups grated Parmigiano-Reggiano a handful at a time, whisking or stirring constantly until the cheese melts into a smooth sauce. If the sauce becomes too thick, add up to 1/2 cup reserved pasta water a few tablespoons at a time to reach a glossy, coating consistency.

Season the sauce with 1 teaspoon salt, 1 teaspoon freshly ground black pepper, and 1/8 teaspoon grated nutmeg. Taste and adjust seasoning as needed.

Finishing

Add the drained fettuccine directly to the pan with the sauce. Toss and gently lift the pasta with tongs or two forks so the sauce evenly coats each strand. If needed, add additional reserved pasta water (a tablespoon at a time) to loosen the sauce for a silky finish.

Cook together over low heat 1–2 minutes, tossing, so the pasta finishes cooking and absorbs some sauce. Be careful not to overcook.

Turn off the heat and stir in 2 tablespoons chopped fresh parsley for brightness.

Serve

Transfer the fettuccine Alfredo to warm plates or a serving bowl. Sprinkle with 1/4 cup extra grated Parmigiano-Reggiano and an extra crack of black pepper. Serve immediately.