In a large pot, bring salted water to a rolling boil. Add the penne pasta and cook according to the package instructions, usually about 11-13 minutes, until al dente. Once tender, drain the pasta in a colander, rinsing with cool water to stop the cooking process, and set aside for later.

While the pasta cooks, place the steak strips in a bowl. Drizzle with olive oil and sprinkle generously with Cajun seasoning, garlic powder, smoked paprika, salt, and pepper. Toss the steak until well coated.

Heat a large skillet over medium-high heat and add butter. Once melted and sizzling, add the seasoned steak strips in a single layer. Sear for 2-3 minutes on each side until browned and cooked to your liking, then remove the steak from the skillet and let it rest.

In the same skillet, add a bit more butter if needed and reduce the heat to medium. Whisk in the flour, cooking for about 1 minute until lightly golden. Gradually pour in the heavy cream and milk, whisking continuously until the mixture is smooth and begins to thicken.

Stir in the mozzarella, Parmesan, and cream cheese into the sauce, mixing until all the cheeses are melted and the sauce is luxuriously creamy.

Carefully add the drained penne pasta to the skillet, tossing it in the cheese sauce. Gently fold in the seared Cajun steak.

Plate your Creamy Cajun Steak Penne Pasta with a sprinkle of fresh parsley and red pepper flakes.