Bring a large pot of salted water to a boil.

Add fettuccine and cook according to package directions until al dente.

While the pasta cooks, melt butter in a large skillet over medium heat.

Whisk in flour until smooth.

Gradually whisk in milk until the mixture is smooth and creamy.

Bring the sauce to a slow bubble, then reduce heat to medium-low.

Stir frequently as the sauce thickens.

Once the sauce has slightly thickened, add cooked shredded chicken and Cajun seasoning.

Season with salt and pepper to taste.

Let the sauce simmer over low heat for a few minutes to allow the flavors to meld.

If the sauce becomes too thick, gently stir in additional milk to reach the desired consistency.

Prepare your desired side dishes, such as broccoli or green beans.

Drain the cooked fettuccine.

Serve the Cajun Chicken Sauce over the fettuccine noodles with vegetable sides.