Begin by generously coating both sides of the chicken breasts with Cajun seasoning, ensuring they are well-seasoned.
Fill a large pot with water, add a pinch of salt, and bring it to a rolling boil. Add the fettuccine pasta and cook according to the package directions until it reaches al dente. Once cooked, drain the pasta, reserving a small cup of pasta water, and set it aside.
In a large skillet, heat the olive oil over medium-high heat. Carefully place the seasoned chicken breasts in the skillet and cook for approximately 7-8 minutes on each side, or until they are cooked through and the juices run clear. Remove the chicken from the skillet and allow it to rest on a cutting board for a few minutes before slicing it into strips.
In the same skillet, reduce the heat to medium, then add the minced garlic. Sauté for about 1 minute, or until fragrant, being careful not to let it burn.
Slowly pour in the heavy cream, stirring to combine, and bring the mixture to a gentle simmer. Gradually incorporate the grated Parmesan cheese, stirring until it has melted and the sauce is smooth and creamy.
Add the cooked fettuccine and the fresh baby spinach into the skillet, tossing everything together to evenly coat the pasta in the rich Alfredo sauce. If the sauce is too thick, add a splash of the reserved pasta water to reach your desired consistency. Continue cooking for an additional 2-3 minutes, or until the spinach has wilted.
Slice the rested chicken and elegantly arrange it on top of the Alfredo pasta.
Season with salt and freshly ground black pepper to taste, then toss gently to combine all the flavors.
Notes
Serve in shallow bowls topped with additional Parmesan and parsley.