It is important to remove as much fat as possible from the tenderloin without damaging the meat.
To trim filet mignon, there are three steps that can be followed in any desired order. The first step is to remove as much fat as possible from the meat without damaging the tenderloin. The second step is to locate and remove a long, irregular strip of tough meat known as a string, and optionally remove a small piece of meat known as an ear, which alters the shape of the filet mignon. The final step involves removing a very tough sheet of tendon known as silver skin. After that, what remains is the edible part of the filet mignon.
The last step necessary to trim the tenderloin is to remove the silver skin, the thick, translucent, smooth white sheet that covers most of one side.
Before starting to cut the beef tenderloin, it is important to have a very sharp knife and towels or napkins to keep the handle and hands of the knife dry to avoid accidents and leave the meat as intact as possible. The loin has two ends, the larger of which is known as the butt; the thinner end is called the tail. Most cuts should start at the thickest end and work toward the tail, usually in short, controlled slices.
The first step in cutting beef tenderloin is to remove any visible surface fat. There will be several areas of fat that can be cut, sometimes taking a small amount of edible meat with them. Most notably, there is a large area of fat just below the end of the tenderloin. Some of the fat cannot be removed from the meat without piercing the surface, so it is normal for some areas of fat to remain.
Then there is an area with a different texture than the rest of the meat; this is known as a chain. The chain is a thin, very strong muscle that runs the entire length of the filet mignon. Starting at the end, the top of the chain is firmly attached and can be difficult to separate; once released, the rest of the chain can be pulled with just your hands. At the tail end of the tenderloin, there may be a long piece of meat that appears to be loose; this is called an ear and can be cut from the filet mignon and saved for later use. These steps are not always done by the butchers who cut the filet mignon.
The last step in trimming the tenderloin is to remove the silver skin. This is a thick, translucent, smooth white sheet that covers most of one side of the filet mignon. It is not edible and can shrink during cooking, folding the meat. It can be separated at a point with a sharp knife and then possibly pulled out with your fingers. If it’s particularly tough, you can use a knife to gently cut off small bits of the silvery skin until it’s completely removed from the filet mignon.