Begin by bringing a large pot of salted water to a rolling boil over high heat. Add the cheese tortellini and cook according to the package instructions until al dente, typically about 3–5 minutes. Drain the tortellini, reserving ½ cup of the starchy pasta water, and set aside.

Pat the steak dry with paper towels to remove excess moisture. Season the steak pieces with Cajun seasoning, smoked paprika, garlic powder, salt, and black pepper. Heat 2 tablespoons of olive oil in a large skillet over medium-high heat until shimmering. Sear the steak bites for 2–3 minutes per side until browned and cooked to your liking, then remove and let rest.

In the same skillet, reduce heat to medium and add 6 tablespoons of unsalted butter. Once melted, add 4 cloves of minced garlic and sauté for 1-2 minutes until fragrant and golden. Stir in ½ teaspoon of red pepper flakes, 1 teaspoon of Dijon mustard, and the juice of one lemon, mixing well.

Return the cooked tortellini and the seared steak bites back to the skillet with the cowboy butter sauce. Toss gently to coat everything evenly, gradually adding reserved pasta water until achieving desired sauce consistency.

Remove from heat and stir in ½ cup of grated Parmesan cheese until melted and well incorporated. Plate immediately, garnishing with extra Parmesan, chopped parsley, and a sprinkle of Cajun seasoning.