Bring a large pot of salted water to a boil. Add the fettuccine pasta and cook according to package instructions until al dente, about 10-12 minutes. Drain the pasta and set aside.
In a large skillet or saucepan, melt the butter over medium heat. Add the minced garlic and sauté for 1-2 minutes until fragrant, being careful not to brown it.
Pour in the heavy cream and bring to a gentle simmer. Cook for 3-4 minutes, stirring occasionally, until the cream slightly thickens.
Reduce the heat to low and gradually whisk in the grated Parmesan cheese until the sauce is smooth and creamy.
Season the Alfredo sauce with salt, black pepper, and ground nutmeg. Stir to combine.
Add the cooked pasta to the sauce and toss gently to coat evenly.
Allow the pasta Alfredo to cool to room temperature.
Transfer the pasta Alfredo to an airtight container and refrigerate for up to 2 days.
To reheat, place the pasta Alfredo in a skillet over low heat. Add 2-3 tablespoons of milk or cream to loosen the sauce if needed. Stir gently until heated through, about 5-7 minutes.
Sprinkle chopped fresh parsley over the pasta before serving.