Most beef cuts for purchase have already been trimmed of fat, but some may still have a noticeable layer. A little fat helps the meat stay moist during cooking and can be easily removed with a sharp knife before serving.
If I’m cooking grain-fed lamb or meat from older animals, I like to cut off lamb fat completely to offset a somewhat gamy flavor.
Pork tenderloin has a thick membrane, called silver skin, attached. To remove it, insert a thin-bladed knife between the meat and membrane near the tapered end of the meat. Keep the edge tilted slightly up against the silver skin, and cut along its length to remove it. Today’s pork is perfectly safe to eat when served medium rare. Overcooked pork will be dry.