Step 1: Cook the rotini in salted boiling water according to package directions until al dente. Drain and set aside.

Step 2: In a large skillet, brown the ground beef over medium-high heat, breaking it apart with a spoon. Once browned, drain any excess grease.

Step 3: Add diced onion to the beef and cook for about 5 minutes until softened. Stir in garlic, Cajun seasoning, smoked paprika, salt, and black pepper. Cook for 1 more minute until everything is fragrant and well coated.

Step 4: In a separate saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1–2 minutes to form a roux. Slowly whisk in the milk, making sure there are no lumps. Bring to a gentle simmer, stirring often, until it starts to thicken.

Step 5: Turn the heat to low and stir in the cream cheese until it melts completely. Add mozzarella and Parmesan, stirring until smooth and creamy.

Step 6: Add the cooked rotini and seasoned beef mixture to the cheese sauce. Stir until everything is well combined and heated through.

Step 7: Serve hot, garnished with more Parmesan and a sprinkle of fresh chives.