For the Chicken:

1. 1. Heat a large skillet over medium-high heat. Add olive oil once hot.
2. 2. Generously coat both sides of each chicken breast with Cajun seasoning.
3. 3. Place the seasoned chicken in the skillet and sear for about 5-7 minutes on each side until a dark crust forms and cooked through. Remove from pan and let rest before slicing.

For the Pasta:

1. 4. Boil a pot of salted water and cook fettuccine according to package directions until al dente. Drain and reserve some pasta water.

For the Alfredo Sauce:

1. 5. In the same skillet used for chicken, lower heat and add heavy cream. Stir gently to scrape any browned bits from cooking the chicken.
2. 6. Gradually add grated Parmesan cheese, stirring until melted and smooth.
3. Combining Everything:
4. 7. Add cooked fettuccine and sliced blackened chicken to the skillet. Toss until well-coated with sauce, using reserved pasta water if needed for consistency.
5. 8. Serve immediately, garnished with fresh parsley and extra Parmesan if desired.