01 - Bring a large pot of salted water to a boil. Cook fettuccine according to package directions until al dente. Reserve 1/2 cup pasta water before draining.
02 - Pat chicken breasts dry with paper towels. Season both sides generously with 1/2 teaspoon salt and 1/4 teaspoon black pepper.
03 - Heat olive oil in a large skillet over medium-high heat. Add chicken and cook 5-6 minutes per side until golden brown and internal temperature reaches 165°F. Transfer to plate and rest 5 minutes before slicing.
04 - Reduce skillet heat to medium. Add butter and minced garlic. Sauté 1 minute until fragrant but not browned.
05 - Pour in heavy cream and bring to gentle simmer. Whisk in Parmesan cheese until completely melted and smooth. Stir in nutmeg. Season with salt and pepper to taste.
06 - Add cooked pasta to skillet and toss to coat evenly. If sauce is too thick, add reserved pasta water one tablespoon at a time until desired consistency is reached.
07 - Add sliced chicken to pasta and toss gently. Serve immediately topped with fresh parsley and additional Parmesan cheese.