The elongated pork tenderloin works well for stuffing because it requires less knife work than thicker, cube-shaped roasts. It also yields attractive slices that are easy to cut and serve unlike the broad slices of a stuffed roast, which can fall apart when you handle them. The tenderloin's compact size and neutral flavor make it an exceptionally quick-cooking, versatile cut of meat suitable for weeknight dinners.
Any ingredients that you enjoy in other pork recipes are likely suitable for pork tenderloin stuffing. Autumnal ingredients such as apples, figs, cranberries, raisins, fennel, mushrooms, chestnuts, rosemary and sage all complement pork. Peppers and tropical fruits such as pineapple and mangoes are good ingredients for summertime grilled tenderloins. Adapt a stuffed tenderloin to an Indian or Thai menu with curried stuffing. Limit the stuffing to two or three main ingredients, like apple-raisin-fennel stuffing or blue cheese and fig stuffing. You need 1 to 3 cups of filling, depending on the size of your tenderloin and how you cut it.
Trim the Tenderloin
A tenderloin has a tough, light-colored membrane called silver skin on one side. Trim silver skin off the tenderloin with a chef's knife if the butcher did not remove it. You can trim fat from the tenderloin if there is any, but removing it is optional. Fat adds flavor and moisture.
Butterfly-Cutting Method: Spiraled Stuffing
Lay the tenderloin vertically on a cutting board. Center the sharp edge of a chef's knife against the side of the tenderloin. Slice into the side of the meat from end to end until you can open the tenderloin like a book. Pound the open tenderloin gently with a meat mallet to flatten it. Spread a 1/2-inch layer of filling across the pork, leaving a 1/2-inch border. Roll the tenderloin, starting at one of the long sides. Roll it tightly without tearing the meat or squeezing the filling out the sides.
Pocket-Cutting Method: A Stuffing Core
Push the tip of a chef's knife halfway into the top of the tenderloin, about 1 inch deep. Pull the knife from one end of the tenderloin to the other, creating a slit in the meat. Begin and end the slit about 1/2 inch away from the ends. The tenderloin should not open like a book. Scoop filling into the slit with a spoon, or pipe a smooth, paste-like filling into the pork with a piping bag. You should be able to hold the stuffed tenderloin closed, concealing the filling entirely.
Tie It Up
Tie pieces of cooking twine around a stuffed tenderloin to hold it together. Leave about 2 inches between the pieces of twine. Season the outside of the stuffed tenderloin, apply a light coat of olive oil or brush it with a sauce, if desired.
Cook to Temperature Not Time
Roasting, broiling and grilling cook pork tenderloin at about the same rate: 20 to 30 minutes per pound. Pork is safe to eat as long as it reaches an internal temperature of 145 degrees Fahrenheit, but stuffed pork tenderloin must reach 165 F to ensure the safety of the filling. You must use a thermometer to accurately gauge the temperature.
Roast, Broil or Grill
Roast stuffed tenderloin at 425 F. Lower the oven temperature to 350 F if the surface starts over-cooking. Broil stuffed tenderloin 4 to 5 inches away from the heat source, turning it with tongs once or twice to achieve an even surface. Grill stuffed tenderloin over indirect heat, slow-cooking it over a two-zone fire. Turn it with tongs two to four times to cook it evenly. Transfer the pork to the direct-heat side of the grill once it reaches an internal temperature of 145 F to sear grill marks on the surface.
Give It a Rest
Remove the tenderloin from the heat when it reaches 165 F. Cover it loosely with aluminum foil and rest it until its internal temperature is 120 F, about 15 minutes. Resting meat enables it to retain its juices more effectively. Do not cut the tenderloin until it reaches 120 F.