Step 1: Cook the Pasta
Bring a large pot of salted water to a boil. Add the rotini and cook until al dente. Drain and set aside while you get the chicken and sauce ready.

Step 2: Season the Chicken
In a bowl, toss the chicken with olive oil, Cajun seasoning, smoked paprika, salt, and pepper until well coated.

Step 3: Sear the Chicken
Melt 2 tablespoons of butter in a large skillet over medium-high heat. Add the chicken and sear for 6–8 minutes, stirring occasionally, until golden brown and cooked through. Transfer the chicken to a plate and set aside.

Step 4: Make the Garlic Butter Base
In the same skillet, melt the remaining 2 tablespoons of butter. Add the minced garlic and cook for about 1 minute, just until fragrant and golden. This adds an extra layer of flavor before the chicken goes back in later.

Step 5: Start the Cheese Sauce
In a separate saucepan, melt the 6 tablespoons of butter over medium heat. Add garlic and sauté for a minute. Sprinkle in the flour and whisk for 1–2 minutes to form a smooth, golden roux.

Step 6: Add the Milk
Gradually pour in the milk while whisking to keep the mixture smooth. Let it simmer for about 5–6 minutes until it thickens slightly.

Step 7: Melt the Cheese
Lower the heat and stir in the shredded cheddar and mozzarella. Keep stirring until fully melted and smooth. Season with Cajun spice, salt, and pepper. Taste and adjust as needed.

Step 8: Combine Pasta and Sauce
Add the drained rotini to the cheese sauce and mix until every piece is coated. If the sauce is too thick, add a splash of milk or pasta water to thin it out.

Step 9: Finish and Serve
Spoon the creamy pasta into bowls and top with the garlic butter Cajun chicken. Sprinkle with green onions for a fresh pop of flavor and color. Serve warm, and don’t be surprised if everyone goes back for seconds.