01 - Bring a large pot of salted water to a boil. Cook pasta according to package instructions until al dente. Drain, reserving 1/2 cup of pasta water, and set aside.
02 - Pat chicken breasts dry and season evenly with salt, black pepper, and garlic powder on both sides.
03 - Heat olive oil in a large skillet over medium-high heat. Cook chicken breasts 5 to 6 minutes per side until golden and cooked through. Remove from skillet, let rest 5 minutes, then slice thinly.
04 - In the same skillet, melt butter over medium heat. Add minced garlic and sauté for 1 minute until fragrant.
05 - Pour in heavy cream and whole milk. Bring to a gentle simmer while stirring continuously.
06 - Lower heat to low. Stir in grated Parmesan and nutmeg if used. Continue stirring until cheese melts and sauce is smooth. Season with salt and pepper to taste.
07 - Add cooked pasta to the sauce and toss to coat. Incorporate reserved pasta water as needed to adjust consistency.
08 - Top pasta with sliced chicken. Garnish with fresh parsley and additional Parmesan. Serve immediately.