Bring a large pot of salted water to a boil. Cook the pasta shells until al dente, as per package instructions. Reserve ¼ cup of pasta water, then drain and set aside.

Pat the steak cubes dry with paper towels. Toss them in Cajun seasoning, salt, and pepper until well coated.

Heat a cast iron skillet over medium-high heat and add olive oil. Sear the steak bites in batches for 2–3 minutes on each side. In the final minute, add butter and minced garlic, tossing to coat. Remove the steak bites and set them aside.

In the same skillet, reduce the heat to medium. Add butter and minced garlic and sauté for 1 minute until fragrant.

Pour in the heavy cream, stirring to deglaze the pan and lift any flavorful bits stuck to the bottom. Allow it to simmer gently.

Add the shredded cheddar, Parmesan, paprika, black pepper, and salt. Stir until the cheese melts and the sauce becomes creamy.

Toss the cooked pasta shells into the cheese sauce. Add the reserved pasta water if needed to loosen the sauce to your desired consistency.

Top with the seared steak bites and garnish with chopped parsley. Serve immediately and enjoy!