Bring a large pot of salted water to a rolling boil and cook the pasta until just al dente

Drain the pasta and set aside, reserving about ½ cup of pasta water

Heat olive oil in a large skillet over medium heat

Add the cooked chicken and lightly sauté for 2–3 minutes to enhance flavor

Remove chicken from skillet and set aside

In the same skillet, melt butter over medium heat

Add minced garlic and cook until fragrant, about 30–45 seconds

Slowly pour in heavy cream and milk while stirring continuously

Allow the mixture to simmer gently for 3–4 minutes until slightly thickened

Gradually add Parmesan cheese, stirring constantly until melted and smooth

Season the sauce with salt, pepper, Italian seasoning, and nutmeg

Stir until the sauce becomes creamy and well blended

Add cooked pasta and chicken back into the skillet

Toss everything together until evenly coated in sauce

Add a splash of reserved pasta water if the sauce feels too thick

Transfer the mixture into a greased baking dish

Spread evenly and top with shredded mozzarella cheese

Preheat oven to 375°F (190°C) and place dish in the center rack

Bake for 20–25 minutes until cheese is melted and bubbling

Switch to broil for 2–3 minutes to achieve a golden crust

Remove from oven and let rest for 5 minutes before serving

Garnish with fresh parsley and serve warm