12 ounces fettuccine or other long pasta
1/4 cup (1/2 stick) unsalted butter
3/4 cup finely grated Parmesan, plus more for serving
Freshly ground black pepper
Cook pasta in a large pot of boiling salted water, stirring occasionally, until very al dente. Drain, reserving 2 cups pasta cooking liquid.
Transfer 1 cup pasta cooking liquid to a large skillet. Bring to a gentle simmer, then whisk in butter, a piece at a time, until melted. Whisking constantly, gradually add cheese, making sure it’s completely melted and incorporated before adding more. Add pasta and toss to coat, adding more pasta cooking liquid as needed, until sauce blankets noodles completely. Serve topped with pepper and more cheese.
From Bon Appetit.