To prepare the carpaccio, trim the beef well of fat and sinew. Wrap tightly in plastic wrap and freeze for at least 30 minutes, or until very firm but not rock-solid. Remove the plastic wrap and using a very sharp, thin knife, slice the meat as thinly as possible. Place each slice between two layers of plastic wrap and lightly pound the slices to flatten them.
Divide the beef between four plates, arranging the slices in a single layer, overlapping them slightly. Cover with plastic wrap and refrigerate until ready to serve.
To make the dressing, whisk together the lemon juice and olive oil. Season to taste with salt and freshly ground pepper and set aside.
Using a vegetable peeler, shave cheese curls from the piece of Parmesan, allowing six shavings per plate. Set aside until ready to use.
Just before serving, toss the rocket leaves in half the dressing and arrange on the plates with the carpaccio. Sprinkle with the Parmesan and capers. Drizzle with the remaining dressing and serve at once with freshly ground black pepper.