1. Pat the steak dry and season both sides generously with Cajun seasoning.

2. Heat olive oil in a cast iron skillet over high heat. Sear steak for 3–4 minutes per side, depending on thickness and desired doneness.

3. In the last minute of cooking, add 1 tablespoon butter and half the minced garlic to the pan. Baste the steak with the melted garlic butter. Remove steak from pan and let it rest.

4. Bring a large pot of salted water to a boil. Add rigatoni and cook until al dente according to package instructions. Drain, reserving 1/4 cup of pasta water.

5. In the same pot over medium heat, melt 2 tablespoons butter. Add remaining garlic and cook until fragrant, about 1 minute.

6. Stir in heavy cream and bring to a gentle simmer.

7. Add mozzarella and Parmesan cheeses. Whisk until fully melted and smooth.

8. Season the sauce with salt, pepper, and crushed red pepper flakes if using.

9. Toss cooked rigatoni into the cheese sauce until fully coated. Add reserved pasta water as needed to adjust consistency.

10. Slice the rested steak against the grain. Plate steak beside or over the pasta.

11. Spoon over any remaining garlic butter from the skillet and garnish with chopped parsley. Serve hot.