1. In your slow cooker, combine the heavy cream, chicken broth, Parmesan cheese, minced garlic, salt, pepper, and nutmeg. Stir until well mixed.
2. Add the butter and diced chicken, if using, to the mixture.
3. Break the fettuccine in half and add it to the slow cooker, making sure it is submerged in the liquid.
4. Cover and cook on low for 2-3 hours, stirring occasionally, until the pasta is tender and the sauce is creamy.
5. Once cooked, give it a good stir to ensure the pasta is well coated with the sauce.
6. Serve hot, garnished with fresh parsley.

Variations & Tips
For a vegetarian version, simply omit the chicken and add your favorite vegetables, such as mushrooms or spinach, during the last hour of cooking. If you have picky eaters, consider serving the pasta plain with the sauce on the side, allowing everyone to customize their own plate. For a bit of spice, add a pinch of red pepper flakes to the sauce. You can also substitute the fettuccine with any pasta shape your family enjoys.