For stovetop:
Heat a cast-iron skillet on medium-high to high and add olive oil. When oil begins to simmer, place steak in skillet and do not move for 5 minutes. Turn it once, and cook for another 3 minutes to medium-rare (or more or less depending on preference).
Transfer steak to a cutting board and let rest, loosely covered with foil, for five minutes. Arrange arugula on a platter. Thinly slice steak on the diagonal, across the grain. Arrange over arugula, then toss remaining ingredients on top. Drizzle dressing on top and serve.
