Cook the fettuccine pasta according to package instructions. Drain and set aside.
In a large skillet, melt butter over medium heat. Add sliced chicken breasts and cook until golden brown and fully cooked. Remove and set aside.
In the same skillet, add minced garlic and sauté until fragrant.
Pour in heavy cream and milk, then bring to a gentle simmer.
Stir in Parmesan cheese, salt, black pepper, and nutmeg. Cook until the sauce thickens.
Return cooked chicken to the skillet and mix well.
Toss in the cooked pasta, ensuring it's fully coated in the creamy sauce.
Garnish with fresh parsley and serve warm.