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, saving about 1 cup of pasta water.

Season the chicken breasts generously with Cajun seasoning. In a large skillet, melt 2 tablespoons of butter over medium heat.

Add the chicken and cook for about 7-8 minutes per side until golden brown and cooked through. Remove the chicken and let it rest before slicing.

In the same skillet, add the remaining butter. Once melted, add minced garlic and sauté for about 30 seconds.

Pour in the heavy cream, stirring continuously until it begins to simmer.

Gradually whisk in the grated Parmesan cheese until melted and the sauce is creamy. If it seems too thick, mix in some reserved pasta water until desired consistency is reached.

Toss in the cooked fettuccine and sliced chicken, ensuring every noodle is coated in the sauce.

Taste and adjust seasoning, adding more Cajun spice if desired.

Garnish with freshly chopped parsley and a sprinkle of extra Cajun seasoning. Serve immediately.