Start by trimming any excess fat from the sirloin steak. Cut the steak into 1-inch cubes and place them in a mixing bowl.
Add salt, black pepper, garlic powder, oregano, onion flakes, and minced rosemary to the bowl. Toss the steak cubes until they are evenly coated with the seasoning mixture.
In a large skillet, melt 2 tablespoons of butter over medium-high heat. Allow the butter to become bubbly, but be careful not to let it brown.
Once the skillet is hot, add the seasoned steak cubes in a single layer. Avoid overcrowding the pan to ensure even cooking. Sear for about 2-3 minutes on each side until a beautiful crust forms and the steak is cooked to your desired level of doneness.
When the steak is almost done, add the minced garlic to the skillet. Sauté for an additional minute, allowing the garlic to infuse its flavor into the steak.
In a mixing bowl, combine the remaining 6 tablespoons of room-temperature butter, grated Parmesan cheese, pinch of salt, minced fresh rosemary, and black pepper. Stir until well blended.
Once the steak is cooked, remove the skillet from heat and transfer the steak bites to the bowl with the Parmesan mixture. Toss to coat the steak in the buttery cheese blend. Serve warm and enjoy the delightful flavors!