Boil a large pot of water with a pinch of salt. Cook the fettuccine according to package instructions.
In a big skillet, melt butter over medium heat. Add minced garlic and cook for 1 to 2 minutes. Stir in heavy cream.
Let the cream reduce for 5 to 8 minutes. Add half of the parmesan cheese, whisk until smooth, and keep it over heat until the cheese melts.
Save some pasta water – it adds flavor and can be used to adjust the sauce consistency.
Toss the alfredo sauce with fettuccine pasta, and sprinkle half of the parmesan cheese. Garnish with the remaining cheese. Add pasta water if needed.
If you like, top it off with Italian parsley.