Cook the Pasta: Bring a large pot of salted water to a boil. Cook the fettuccine according to the package instructions until al dente. Reserve ½ cup of pasta water, then drain the pasta and set aside.

Season and Cook the Chicken: In a bowl, toss the chicken pieces with Cajun seasoning until evenly coated. Heat olive oil in a large skillet over medium-high heat. Add the seasoned chicken and cook for 5-7 minutes, stirring occasionally, until the chicken is browned and cooked through. Remove the chicken from the skillet and set aside.

Prepare the Alfredo Sauce: In the same skillet, reduce the heat to low. Add butter and let it melt. Add the grated garlic and sauté for about 30 seconds, being careful not to burn it. Pour in the heavy cream and let it simmer gently for about 5 minutes, stirring occasionally.

Add Parmesan Cheese: Gradually stir in the grated Parmesan cheese until the sauce is smooth and creamy. Season with salt and pepper to taste.

Combine Pasta and Chicken: Add the cooked fettuccine to the sauce, tossing to coat the pasta evenly. If the sauce is too thick, add a bit of the reserved pasta water to reach your desired consistency. Return the cooked chicken to the skillet and mix everything together until well combined and heated through.

Serve: Garnish with chopped fresh parsley, if desired. Serve hot and enjoy!