Season chicken breast with Cajun seasoning, salt, pepper and a little garlic powder. Pan-sear in butter/oil about 5 7 min per side until cooked, then slice. In the same pan, saute sliced mushrooms and garlic, add 1 cup heavy cream + ½ ¾ cup Parmesan, and simmer until creamy. Toss with cooked fettuccine and a splash of pasta water. Top with sliced chicken and parsley. Serve with toasted buttered garlic bread.