Cook rotini pasta according to package directions until al dente. Drain and set aside.
- Season steak tips with Cajun seasoning.
- Heat olive oil in a large skillet over medium-high heat. Sear steak tips for 2–3 minutes per side until browned and cooked to desired doneness. Remove and set aside.
- In the same skillet, reduce heat to medium and melt butter. Add minced garlic and cook for 1–2 minutes until fragrant.
- Pour in heavy cream and bring to a gentle simmer. Stir in parmesan and mozzarella cheese (if using) until melted and smooth.
- Season sauce with salt and pepper to taste.
- Add cooked rotini pasta to the skillet and stir to coat in the sauce.
- Return steak tips to the skillet and fold into the pasta.
- Garnish with chopped fresh parsley and serve hot.