1. Bring a large pot of salted water to a boil. Cook rotini pasta until al dente according to package directions. Drain and set aside, reserving ½ cup of pasta water.

2. In a large skillet over medium-high heat, add olive oil and cook ground beef until browned. Drain excess fat if needed.

3. Push the beef to one side and add diced onion. Cook for 2–3 minutes, then stir in minced garlic and cook for another 30 seconds.

4. Sprinkle in Cajun seasoning and stir everything to coat. Cook for 1 minute to toast the spices.

5. Reduce heat to medium. Pour in heavy cream and beef broth, stirring to combine. Let it simmer for 5–7 minutes until slightly thickened.

6. Add the cooked rotini to the skillet and toss with the sauce. Stir in Parmesan cheese until melted and the sauce clings to the pasta.

7. If the sauce is too thick, add a splash of reserved pasta water. Season with salt and pepper to taste.

8. Garnish with parsley or green onions, if using, and serve warm.