- On a plate, rub the meat on both sides with the dry rub. Let sit at room temperature for 1 hour.
- Preheat the grill, setting the burners to medium-high. Oil the grate.
- Brush the meat with the oil. Place on the grill, close the lid and cook for 18 minutes, or until a thermometer inserted into the centre of the meat reads 118°F (48°C) for rare. Turn a few times during cooking. Remove from the heat and place on a clean plate. Cover lightly with aluminum foil and let rest for 10 minutes.
- Turn the burners on the grill to high.
- Dab the meat with paper towels and place it back on the grill. Cook for 1 minute per side to obtain grill marks.
- Place the butter on the steak and finish with the chives and fleur de sel. Add pepper to taste. Serve immediately.