The pork tenderloin is the filet mignon of pork. It is very tender and lean and can be used anywhere you can use chicken. A tenderloin weighs about 1 lb for each. When grilling, it must reach an internal temperature of 145º and rest for three minutes following grilling. Pork tenderloins are classified as "extra lean" by the USDA. A serving size is 3 ounces, which is about the size of a deck of cards. There are many different ways you can cook a tenderloin including grilling, baking and sauteing. You can use the tenderloin to make pork kabobs, medallions, stir fry or simple marinate. Some of the best marinades and seasonings for pork tenderloins include Italian dressing, teriyaki, and dry rubs.