In a large pot or deep skillet, melt the butter over medium heat. Add the minced garlic and sauté until fragrant (about 1 minute).
Add Broth and Cream:
Pour in the chicken or vegetable broth and heavy cream. Stir to combine and bring to a gentle simmer.
Cook the Pasta:
Add the uncooked fettuccine to the pot, making sure it’s fully submerged. Reduce the heat to medium-low and cook for 12–15 minutes, stirring occasionally to prevent sticking. Cook until the pasta is al dente.
Incorporate Cheese and Seasonings:
Once the pasta is tender, reduce the heat to low. Stir in the Parmesan cheese, salt, pepper, and nutmeg (if using). Continue stirring until the sauce thickens and coats the pasta.
Add Optional Ingredients:
If you’re adding cooked chicken, shrimp, or vegetables, stir them in now and heat through for 2–3 minutes.
Serve:
Garnish with freshly chopped parsley and extra Parmesan cheese. Serve warm.