Brush the meat thinly with sunflower oil.
Heat the grill or pan strongly and sear the meat on both sides between 90 and 120 seconds.
Place on the grill in the indirect heat and bring to the desired core temperature at 140 °C (medium 55-57 °C, done 65 °C). When preparing in the oven, place the meat in at 140 °C and proceed in the same way. This may take 30-45 minutes for thick steaks.
After reaching the desired core temperature, let the meat rest for another 5-10 minutes.
Slice against the grain and season with sea salt flakes and pepper.