Remove steak from the refrigerator. Cut with the grain to slice the picanha cut into four steaks, leaving a fat cap on each steak. Salt generously on all sides, using your fingers to press the salt into the meat. Then, let rest at room temperature for 45 minutes.
Preheat oil in a large cast-iron skillet over medium-high heat.
Place the steaks in the skillet, fat side down (if you don't have enough room, cook just two at a time). Sear until golden brown, about 2-3 minutes.
Flip to the other side and sear for another 2-3 minutes.
Check the internal temperature to see if the steaks are at your desired level of doneness (130-135 degrees for medium-rare). If not, reduce heat to low and allow to cook another 1-2 minutes.
Remove steaks from heat and rest at room temperature for 5-10 minutes before serving.