Step 1: Bring a large pot of salted water to a boil. Add the pasta shells and cook until al dente, about 9 to 10 minutes. Reserve half a cup of pasta water before draining. Set the pasta aside and keep it warm.

Step 2: Pat the steak strips dry using paper towels. This helps the steak sear properly instead of steaming. Season the steak evenly with Cajun seasoning, garlic powder, smoked paprika, salt, and black pepper. Toss gently to coat every piece.

Step 3: Heat olive oil and 1 tablespoon butter in a large skillet over medium-high heat until hot. Add the steak strips in a single layer, making sure not to overcrowd the pan. Sear the steak for about 1 to 2 minutes per side, until nicely browned and cooked to your preferred doneness. Remove the steak to a plate and keep warm.

Step 4: In the same skillet, melt the remaining 2 tablespoons of butter over medium heat. Add the minced garlic and sauté for 30 to 45 seconds, stirring constantly, just until fragrant. Be careful not to burn it.

Step 5: Pour in the heavy cream and milk, stirring to combine. Add the cream cheese and whisk continuously until it melts fully and the sauce becomes smooth and creamy.

Step 6: Stir in the freshly grated Parmesan and shredded mozzarella cheeses. Add the remaining ½ teaspoon of Cajun seasoning for an extra layer of spice. Keep stirring gently over low heat until all the cheeses melt smoothly into the sauce and it thickens to a luscious, glossy consistency. Taste and adjust salt and pepper as needed.

Step 7: Add the cooked pasta shells to the sauce. Toss everything gently but thoroughly so that each shell is coated with the creamy, cheesy Cajun sauce. If the sauce feels too thick, stir in a splash of the reserved pasta water to loosen it just enough for perfect coverage without being runny.

Step 8: Spoon the cheesy pasta shells into serving bowls or plates. Arrange the tender Cajun steak tips on top or alongside, spooning any extra sauce over the steak for that added indulgence.

Step 9: Garnish with freshly chopped parsley. The bright green adds a fresh pop of color and a hint of herbal brightness to balance the rich, smoky flavors.