Bring your steak to room temperature 30 minutes before cooking.
Prepare chimichurri sauce: combine all ingredients except olive oil, lemon juice and lemon zest in a food processor. Pulse until finely chopped.
Transfer processed mixture to a bowl, stir in olive oil, lemon juice, lemon zest and season with salt and pepper to taste. Set aside and let sit for 10 minutes.
Brush your steak with olive oil and season generously with salt and pepper.
Preheat a large cast-iron skillet over medium heat. Raise the heat to high and add the steak. For medium - cook 8 minutes on one side and 5 minutes on the other side. Hold the steak with tongs and sear the edges. Transfer your steak to the cutting board, cover with foil, and let rest for 5 minutes.
Slice against the grain, transfer to a serving plate, pour 3 tbsp of chimichurri over the steak and enjoy!