Place the beef slices on a cutting board and gently pound the meat with the heel of your hand or a meat mallet until paper think. Divide the meat evenly among 4 chilled plates. Drizzle with olive oil and salt to taste. Squeeze ½ lemon over the top of the carpaccio and roll each carpaccio slice into small spheres and stand on end. Add a few drops of white truffle oil and shave the truffles over the carpaccio. Serve immediately with rocket and crusty bread.