Tightly wrap the beef and place it in the freezer for about 15 minutes or so until it's slightly frozen but not solid. Doing so allows you to cut the meat easily.
Using a sharp knife or slicer, cut your beef paper-thin. It must be so thin that you'll be able to look through it when you hold the slice up.
Place the beef you've just sliced on a cold plate. You’ll need the plate to be cold as you work, so I suggest putting a bag of frozen vegetables underneath it to keep the temperature constant.
Add the capers, arugula, and mixed greens on the plate atop the beef. Drizzle a generous amount of oil and your favorite vinaigrette. Top it off with black pepper and salt to taste. Serve immediately and enjoy!