Bring a large pot of salted water to a boil. Cook penne pasta according to package instructions for 10-12 minutes, then drain and set aside.

Toss steak strips with olive oil, Cajun seasoning, garlic powder, smoked paprika, salt, and pepper in a mixing bowl.

Heat a skillet over medium-high heat, add butter, and sear seasoned steak strips for 2-3 minutes per side until golden brown.

Add minced garlic to the skillet and sauté for 30 seconds. Remove garlic and set aside with the steak.

Melt another tablespoon of butter in the skillet, whisk in flour, and cook for 1 minute. Gradually add heavy cream and milk, stirring until thickened in 3-5 minutes.

Stir in mozzarella, Parmesan, and cream cheese until melted and creamy.

Add the cooked penne to the sauce, tossing to coat. Stir over low heat for 1-2 minutes.

Plate the dish, top with seared steak, and garnish with parsley, cheese, and red pepper flakes if desired.