Creating Buttery Garlic Sirloin is a straightforward process. Just follow these simple steps:

1. Prepare the Steak: Remove the sirloin from the refrigerator and let it come to room temperature for about 15 minutes. This ensures even cooking.
2. Season the Steak: Generously season both sides of the sirloin with salt and black pepper.
3. Heat the Pan: In a large skillet, heat 2 tablespoons of butter over medium-high heat until melted and hot.
4. Sear the Steak: Add the sirloin to the skillet and cook for about 4-5 minutes on each side for medium-rare, or adjust to your desired doneness.
5. Add Garlic: In the last minute of cooking, add the minced garlic to the pan, allowing it to sauté in the butter.
6. Baste the Steak: Tilt the skillet slightly and use a spoon to baste the steak with the garlic butter for extra flavor.
7. Rest the Steak: Once cooked to your liking, transfer the steak to a cutting board and let it rest for 5 minutes.
8. Make the Sauce: In the same skillet, add the remaining 2 tablespoons of butter and let it melt. Stir in the chopped parsley and red pepper flakes if using.
9. Slice the Steak: After resting, slice the sirloin against the grain into thin strips.
10. Serve: Drizzle the garlic butter sauce over the sliced steak.

By following these steps, you will create a deliciously flavorful Buttery Garlic Sirloin that is sure to impress.