Boil the salted pasta shells until they reach al dente. Reserve 1/2 cup of the pasta water before draining.

Pat the steak cubes dry and season generously with salt, pepper, and optional Cajun or steak seasoning.

Heat olive oil in a large skillet over medium-high heat. Sear the steak bites in a single layer for 2-3 minutes on each side until browned to your liking. Remove and set aside.

Lower the heat and add 2 tablespoons of butter and minced garlic to the skillet. Sauté until fragrant, about 30 seconds.

Add the seared steak back to the skillet and toss to coat in the garlic butter, then set aside again.

In a separate pan, melt the remaining tablespoon of butter. Combine cream, broth, garlic powder, cream cheese, and Parmesan, stirring until smooth and creamy.

If using mozzarella, add it now. Adjust flavor with salt and pepper, then fold in the cooked pasta shells until well-coated, adding reserved pasta water if needed.

Plate the creamy Parmesan shells and top them with garlic butter steak bites. Drizzle extra garlic butter from the skillet over everything.

Garnish with chopped parsley and additional Parmesan if desired.