Chop romaine lettuce, or lay out smaller romaine leaves on a large platter.
Season the steak generously with Kosher salt and black pepper. A thick steak can take a heavy coating of Kosher salt!
Heat a cast iron skillet over high heat. Wait until the skillet is smoking before adding the oil and and the steak. We want an extremely hot surface to give the meat a dark crust without overcooking the steak. Cook for 3-5 minutes, until the steak has formed a nice sear.
Flip the steak, and cook on the other side for an additional 3-5 minutes, until both sides have a nice char. If desired, use an internal temperature probe to check for desired doneness. See chart in post for cooking temperatures.
Allow the steak to rest for about 10 minutes while preparing the rest of the salad.
Once the rest of the salad is ready, thinly slice the steak.
Drizzle the romaine leaves with the caesar dressing. If using chopped up romaine, add it to a bowl, drizzle with dressing, and then toss the lettuce to coat.
Top the romaine with sliced steak and optional heirloom tomatoes. Add parmesan crisps if serving the salad right away, or serve them on the side for people to add to their plates along with the salad.