Rinse meat well. Trim away some of the fat to remove the silvery cartilage underneath.
Sprinkle meat generously with Lawry’s. You can much more liberally season a tenderloin, because you’re having to pack more of a punch in order for the seasoning to make an impact. Start with Lawry’s Seasoned Salt. Rub it in with your fingers. Sprinkle both sides generously with lemon & pepper seasoning. (There are no measurements because it depends on your taste, but be sure to season liberally.)Place the peppercorns in a Ziploc bag, and with a mallet or a hammer or a large, heavy can, begin smashing the peppercorns to break them up a bit. Set aside.
Heat some olive oil in a heavy skillet. When the oil is to the smoking point, place the tenderloin in the very hot pan to sear it. Throw a couple of tablespoons of butter into the skillet to give it a nice little butter injection before going in the oven. A minute or two later, when one side is starting to turn nice and brown, flip and repeat.
Place the tenderloin on an oven pan with a rack. Sprinkle the pummeled peppercorns all over the meat. Press the pepper onto the surface of the meat. Put several tablespoons of butter all over the meat. Stick the long needle of the thermometer lengthwise into the meat. Place it in a 475-degree oven until the temperature reaches just under 140 degrees, about fifteen to twenty minutes. Stay near the oven and keep checking the meat thermometer to make sure it doesn’t overcook. Let meat stand ten minutes or so before slicing, so the meat will have a chance to relax a bit.
To serve, you can spoon the olive oil/butter juices from the skillet onto the top of the meat for a little extra flavor.