No matter what part of the whole tenderloin your cut comes from, it's a good idea to tie the meat with kitchen twine before cooking. A tenderloin's thickness varies quite a bit from end to end, particularly if the cut includes the narrow tail. Cinching the meat at one- or two-inch intervals will give it a uniform shape and thus ensure even cooking. Robert Esposito, a third-generation butcher at the New York City shop Giovanni Esposito & Sons, demonstrated his method of tying, which he does after removing the tough muscle known as the chain, any excess fat, and the layer of connective tissue called silver skin.