Let the steak sit at room temperature for about 1 hour before cooking.
Preheat your grill to high heat, aiming for about 450°F (230°C).
Rub the steak with olive oil and season generously with salt and black pepper on both sides.
Place the steak on the grill and sear for about 4-5 minutes on each side until a nice crust forms.
Move the steak to indirect heat, add rosemary sprigs on top, and continue grilling to desired doneness, turning occasionally.
Use a meat thermometer to check for doneness: 130°F (54°C) for medium-rare, 140°F (60°C) for medium.
Remove the steak from the grill, cover with foil, and let it rest for 10 minutes before slicing.