In a large ziploc bag, add the ingredients for your marinade and let it rest in the fridge for an hour at the very least. Pull out about 30 minutes before you intend to grill.
Preheat your grill or grill pan to 400-425 degrees F. Grill steak 8 minutes on the first side, then flip and grill another 6 minutes for medium. Place aside, cover with foil, and allow it to rest for 10 minutes
Meanwhile place all your ingredients, except the salt and olive oil in a food processor. Pulse till everything is finely chopped, then add olive oil and blend till just combined. Taste and add salt as needed. If you like more tanginess, add a little more vinegar.
Once the steak has rested, cut it against the grain (in the opposite direction of where you see the “lines”). This will allow for a more tender steak. Top with chimichurri.