Cook the fettuccine according to package directions, then drain and set aside.

While the pasta cooks, melt butter in a large skillet over medium heat, then add cubed chicken and cook until browned and cooked through.

Stir in minced garlic and cook for another minute until fragrant, then pour in the heavy cream and bring to a gentle simmer.

Reduce heat to low, then gradually stir in the grated Parmesan cheese until melted and the sauce is smooth.

Season the sauce with salt and black pepper to taste, then add the cooked fettuccine and chicken to the skillet, tossing to coat evenly.

Serve immediately, garnished with extra Parmesan cheese and fresh parsley if desired.