Season the sirloin steak with salt and black pepper on both sides. Allow it to sit at room temperature for about 15 minutes.

In a small saucepan over medium heat, melt the unsalted butter. Add the minced garlic and sauté for about 2-3 minutes until fragrant but not browned. Remove from heat and stir in the chopped parsley and lemon juice.

Preheat your grill or skillet over high heat and add the olive oil to prevent sticking.

When the grill is hot, add the steak and cook for about 5-7 minutes on each side for medium-rare, or longer if desired. Use tongs to turn the steak as necessary.

During the last few minutes of cooking, brush the garlic butter mixture generously over the steak to infuse it with flavor.

Once done, remove the steak from the grill and let it rest for about 5 minutes to allow the juices to redistribute.

Slice the steak against the grain into thick slices and drizzle any leftover garlic butter on top before serving.

For a more intense flavor, consider marinating the steak in the garlic butter mixture for a few hours or overnight in the refrigerator.

Adjust cooking times based on your preference for doneness, using a meat thermometer for best results (130°F for rare, 145°F for medium, 160°F for well done).