Prepare beef tenderloin by trimming (if it didn’t come trimmed). You can purchase just a portion of a beef tenderloin (you will want the thick, evenly round end) as only about 1 pound is needed for this dish. Purchase tenderloin fresh the day you will prepare the dish.
If tenderloin is already tied, go ahead and remove the ties as they will get in the way of slicing.
Use a pastry brush to slather the tenderloin with the mustard.
Grind whole peppercorns and spread them on your work surface. Roll the mustard-smothered tenderloin in the freshly cracked pepper to coat the full exterior.
In a cast iron skillet, heat the butter and 2 tablespoons of olive oil until they begin to sizzle.
Sear the tenderloin in the hot skillet, cooking for just a minute on each side - just enough to sear the very outside and toast the pepper crust.
Immediately remove the tenderloin from the skillet and wrap in plastic wrap. Pull the plastic wrap taut around the tenderloin to form a nice evenly round shape.
Place the tenderloin in the freezer for 1-2 hours, long enough for it to firm up but not freeze solid.
When ready to serve, remove the tenderloin from the freezer. Unwrap the plastic wrap.
Using a very sharp knife, slice very thin slices off the tenderloin. You are aiming for 2-3 mm thick.
Place the slices of meat on a cutting board or on a sheet of parchment paper or plastic wrap. Place another piece of parchment or plastic wrap over the slices.
Use a rolling pin to gently press the meat into paper thin sheets.
Arrange the meat on a cutting board or serving tray.
Drizzle with olive oil.
Garnish with a sprinkle of salt, capers, and baby arugula.
Serve or refrigerate immediately. Squeeze fresh lemon juice over the dish just before serving.
Notes
Storage:Beef carpaccio should be consumed the same day it is prepared.Notes:The beef tenderloin should be purchased from a reputable butcher or market. It is a high-end cut of meat.To reduce the risk of bacteria growth, purchase the tenderloin the same day you intend to prepare the beef carpaccio and keep it refrigerated at all times. Slice the meat yourself at home rather than having the butcher do it.Beef carpaccio can also be prepared by skipping the seared crust.Freeze the tenderloin for 1-2 hours before slicing it to help it hold its shape.Use a very sharp knife or a serrated knife to slice the meat and be very careful.Since a beef tenderloin is such a tender piece of meat, it flattens out as easily as rolling soft butter when you place it between parchment or wax paper and roll it gently with a rolling pin. No need to pound it out or even put a lot of pressure on the rolling pin.The lemon juice will “cook” the beef - much like when you “cook” fish for ceviche using citrus juice. Give the prepared dish a squeeze of lemon immediately before serving.