Bring a large pot of salted water to a boil. Cook the fettuccine according to package directions until al dente. Drain, reserving a splash of pasta water.

In a large skillet over medium heat, melt the butter. Pour in the heavy cream and simmer gently for 2-3 minutes.

Stir in the Romano and Parmesan cheeses slowly, whisking until the sauce is smooth and creamy.

Season the sauce with salt and freshly ground pepper. If the sauce is too thick, add a little reserved pasta water to reach desired consistency.

Add the drained fettuccine to the skillet and toss to coat thoroughly in the Alfredo sauce.

Serve immediately, garnished with extra grated Parmesan and a sprinkle of chopped parsley if desired.