01 - Bring a large pot of salted water to a boil. Cook fettuccine until al dente according to package instructions. Reserve 1/2 cup of pasta water, then drain the pasta.
02 - Melt butter in a large skillet over medium heat. Add minced garlic and sauté until fragrant, about 1 minute.
03 - Pour in heavy cream and bring to a gentle simmer. Stir frequently and cook for 2 to 3 minutes until slightly thickened.
04 - Reduce heat to low. Stir in grated Parmesan, salt, pepper, and nutmeg if using, until cheese melts and sauce is smooth.
05 - Add drained fettuccine to the skillet and toss to coat evenly. Adjust sauce consistency by adding reserved pasta water gradually as needed.
06 - Plate immediately and garnish with freshly chopped parsley and extra Parmesan if desired.