1. Season chicken with Cajun seasoning, salt, and pepper.

2. Heat olive oil in a skillet and sear the chicken until golden brown and cooked through. Set aside to rest, then slice.

3. Bring a large pot of salted water to a boil and cook spaghetti until al dente. Drain, reserving 1 cup of pasta water.

4. In the same skillet, melt butter and sauté minced garlic until fragrant.

5. Stir in flour to make a roux, cooking for 1 minute.

6. Gradually whisk in the milk until smooth.

7. Add mozzarella and Parmesan cheese, stirring until melted and combined.

8. Pour in heavy cream and simmer until the sauce thickens.

9. Add cooked spaghetti to the sauce and toss to coat. Use reserved pasta water to loosen if needed.

10. Top with sliced chicken and garnish with fresh parsley. Serve hot.