Heat a skillet over medium-high heat. Add olive oil and butter. Once shimmering, season steak tips with Cajun seasoning and sear for 3-4 minutes on each side. Remove and let rest.

In a large pot, bring salted water to a boil. Add rigatoni and cook for 10-12 minutes until al dente. Reserve ½ cup pasta water, then drain rigatoni.

In the same skillet, melt remaining butter over medium heat. Sauté minced garlic for 1-2 minutes until fragrant.

Pour in heavy cream and bring to a simmer. Gradually stir in Parmesan cheese until melted. Add optional cheese and season sauce with salt and pepper.

Toss rigatoni into the creamy sauce, mixing well. Add reserved pasta water if sauce is too thick.

Gently fold in seared steak tips. Heat together for 1-2 minutes.

Serve immediately, garnished with additional Parmesan cheese, black pepper, or hot sauce.