Preheat oven to 425° and lightly grease a heavy rimmed baking sheet.
Prepare Beef Tenderloin:
Whole beef tenderloin is not even in size throughout and it’s covered in some fat. The fat layer is actually very easy to peel off. What will not be as easy to peel off is the silver skin that’s underneath.
Peel off the fat layer off the tenderloin.
To remove silver skin, pull up some of the silver skin at one end of the tenderloin and then use a thin knife to cut along the silver skin to separate it from the meat. Be careful not to remove any of the actual meat.
Once the fat and silver skin is removed, you have two choices, prepare the WHOLE beef tenderloin, which includes the the wing that's attached to the thicker part and the thin tip at the other end, or trim.
To trim the tenderloin, you can trim the wing and the tip end at the point where it starts to get narrow and use that meat for kebabs, searing it for a sandwich, or searing it for an appetizer.
To prepare the whole tenderloin, you would need to make it as even as possible for cooking. Pull up the narrow end of the tenderloin and fold it into the meat. Use cooking twine to tie it together. Make sure to tie the wing to the main meat as well. This will create a more uniform size throughout the steak.
Tie the tenderloin with a kitchen twine around in several spots, about every 2-3 inches. Tying the tenderloin will ensure even cooking because it will help keep the shape of meat uniform.
Rub tenderloin with a little bit of olive oil all over.
To crack whole peppercorns, you can use a coarse setting on the pepper mill, pulse it a few times in a spice grinder, or use a heavy cast iron skillet to crack it by hand on the cutting board.
Spread all the seasoning on the parchment paper, add grated Parmesan cheese, mix it evenly, and place the tenderloin on top of the seasoning. Roll the tenderloin around to coat it evenly in seasoning and press on the seasoning to stick it on better.
Cooking Beef Tenderloin:
Once beef tenderloin is tied and coated with seasoning, place it onto the baking sheet.
Insert a leave-in thermometer into the thickest part of the meat. (I highly recommend that you use a leave in thermometer to track meat temperature more accurately.)
*If you do not have a leave-in thermometer, take the tenderloin out of the oven to measure the temperature and close the oven so the oven temperature doesn’t lower. Remember to take the temperature of the center, at the thickest part.
Cook beef tenderloin until it reaches 130°-135° for medium-rare or 140°-145° for medium.
Take the tenderloin out of the oven and transfer onto the cutting board. Loosely tent with a sheet of aluminum foil and let it rest for 10-15 minutes before cutting.
Slice tenderloin into about 1/2 inch slices, against the grain.