Combine the lemon zest, salt, and rosemary leaves on a cutting board. Chop the ingredients together to form fine crumbs.

Drizzle the steak with the olive oil and sprinkle with the salt, then sprinkle both sides of the steak with the rosemary mixture. Press the coating into the steak with your hands.

Let the steak rest for 15 minutes (or longer in the fridge if you have time). To cook, preheat a grill pan or grill to medium-high heat.

Grill on both sides, turning only once, until the meat develops a nice crust or grill marks. For 1-inch steaks, 4 minutes on each side is usually perfect for medium-rare steak.

Allow the steak to rest for at least 10 minutes, then thinly slice against the grain. Serve with lemon wedges and arugula, if using.