Bring a large pot of salted water to a boil. Add the fettuccine and cook according to package instructions until al dente. Drain and set aside, reserving a little pasta water.

Season the chicken breasts with Cajun seasoning, salt, and pepper.

In a large skillet, heat olive oil over medium heat and sear the chicken for 6-7 minutes on each side until fully cooked and golden brown. Remove from skillet and let rest.

In the same skillet, sauté garlic for about 1 minute until fragrant.

Pour in the heavy cream and bring to a gentle simmer. Stir in the Parmesan cheese until melted and smooth. Adjust thickness with reserved pasta water as needed.

Slice the cooked chicken and return it to the skillet. Add the drained fettuccine, tossing gently to coat everything with the sauce.

Garnish with chopped parsley and serve hot.