1. Pat the beef cubes dry with paper towels. Toss in a bowl with Cajun seasoning, garlic powder, smoked paprika, salt, and black pepper. Let it marinate for 10–15 minutes.

2. Bring a large pot of salted water to a boil. Add the rotini and cook until al dente, about 8–10 minutes. Drain and set aside, reserving ½ cup of pasta water.

3. Heat olive oil and butter in a cast iron skillet over medium-high heat. Add beef cubes in a single layer and sear for 2–3 minutes per side until browned and cooked through. Remove and rest.

4. In a saucepan, melt 2 tbsp butter over medium heat. Add minced garlic and sauté for 30 seconds. Stir in flour to create a roux and cook until golden, 1–2 minutes.

5. Slowly whisk in the milk and heavy cream. Simmer until thickened. Gradually add cheddar and Parmesan, stirring until smooth. Season with Italian seasoning, red pepper flakes, salt, and pepper.

6. Stir in the cooked rotini and mix until well coated. Add a splash of pasta water if the sauce needs thinning.

7. Plate the creamy rotini, top with Cajun beef, and garnish with parsley and extra Parmesan. Serve hot.