Trimming a pork tenderloin is easy. All you need is a small sharp knife and a little patience. The same technique applies to beef tenderloin, as well.
First, locate the small fatty “chain” of meat that runs along side the full tenderloin and cut it away. I also trim off the pointed end because it doesn’t cook evenly, but if you prefer you can tuck and tie it under the rest for roasting. Save these pieces for another use, such as stir fry, ground pork, or au jus.
Next, trim off as much of the surface fat as you like. I take off as much as I can. Locate the tough shiny membrane called the “silver skin”. This membrane can be a little tricky to remove but it has to go. Starting at the end of the silver skin that leads toward the center of the meat, slip your knife under the membrane to begin your cut. Hold the blade of the knife on an upward angle to shave the silver skin away while taking as little meat as possible. You may have to remove the silver skin in strips.
Discard the silver skin, but save the rest of the scraps for later. Your tenderloin is now trimmed and ready to cook as you like.