Cook the rigatoni pasta according to package instructions. Drain and set aside.

In a large skillet, heat olive oil over medium-high heat and add Cajun-seasoned steak tips. Cook until browned and cooked to your preferred doneness. Remove and set aside.

In the same skillet, add butter, diced onion, and minced garlic. Sauté until the onion is translucent.

Stir in the heavy cream and bring to a simmer.

Add the cooked rigatoni and mix in Parmesan cheese until melted and creamy.

Fold in the cooked steak tips, season with salt and pepper to taste, and serve hot.