Instructions
Step 1
Dry the steak with paper towels if needed. Season all over with salt and black pepper, ensuring that it thoroughly sticks to the meat. Set aside to come to room temperature, at least 20 minutes.
Step 2
In a medium bowl, stir together the anchovies and their oil, 2 tablespoons of olive oil, the garlic, and rosemary.
Step 3
Make the salad dressing: In a large bowl, stir together the shallot, vinegar, and a pinch of salt.
Step 4
Place a large cast-iron or stainless-steel skillet over medium heat. Brush the steak with a little oil from the anchovy mixture (avoid any solids at this point). Add 1 tablespoon of olive oil to the skillet and turn the heat to medium-high. When the oil begins to smoke, carefully add the steak and cook, pressing down on the bone with tongs to help the steak remain in contact with the skillet, until a very dark crust forms on the bottom, about 6 minutes. Flip the steak and cook until the other side is deeply browned, about 3 minutes. Turn the steak to press its fatty sides up against the skillet until browned, about 1 minute more.
Step 5
Transfer the steak to a cutting board and immediately brush all over with the remaining anchovy mixture. Set aside to rest for 6–8 minutes.
Step 6
Make the salad: In the bowl with the shallot mixture, whisk in the olive oil. Add the watercress, season to taste with salt and black pepper, and toss gently to coat.
Step 7
Using a chef’s knife, cut the meat away from the bone and into two pieces by following the lines of the center bone. (Reserve the bone.) Starting from one end, slice each piece of meat about ½ inch thick against the grain, keeping it in the shape of the original steak.
Step 8
Transfer the salad to one side of a large platter. Add the steak bone to the other side of the platter and nestle the two halves of meat back into the bone, overlapping slightly with the salad. Drizzle the meat with juices from the cutting board, top the salad with the pistachios and parsley (if desired), and serve immediately.