01 - Bring a large pot of salted water to a boil. Add the fettuccine and cook according to package instructions until al dente. Reserve 1/2 cup of pasta water, then drain the pasta.
02 - While the pasta cooks, melt the butter in a large skillet over medium heat. Add the minced garlic and cook for 1 minute, until fragrant but not browned.
03 - Pour in the heavy cream and bring to a gentle simmer. Stir occasionally and cook for 2–3 minutes.
04 - Reduce the heat to low. Add the grated Parmesan cheese in small batches, stirring constantly until the cheese is melted and the sauce is smooth. Season with black pepper and nutmeg, if using.
05 - Add the drained fettuccine to the skillet and toss to coat in the sauce. Add a splash of reserved pasta water if needed to reach your desired sauce consistency.
06 - Serve immediately, garnished with chopped parsley and extra Parmesan.