Bring a large pot of salted water to a rolling boil over high heat. Add fettuccine pasta and cook according to package instructions for 8-12 minutes, until al dente. Reserve about half a cup of pasta water, drain the rest, and set pasta aside.

In a large skillet, heat 1 tablespoon of olive oil over medium-high heat. Add sliced or cubed chicken breast seasoned with Cajun seasoning. Cook for about 6-8 minutes, stirring occasionally, until golden brown and no longer pink in the center.

Reduce heat to medium-low, pour in 1 cup of heavy cream into the skillet with cooked chicken. Whisk in freshly grated Parmesan cheese until smooth and creamy. Let sauce simmer for 2-3 minutes until thickened.

Add reserved fettuccine to the skillet with sauce. Toss gently until pasta is thoroughly coated. If the sauce is too thick, add a splash of reserved pasta water until desired consistency is achieved.

Serve hot, garnished with freshly chopped parsley or sliced green onions. Optionally pair with a fresh side salad or garlic bread.