Heat oven to 475 degrees.
Let tenderloin rest at room temperature 1 hour. Pat meat with paper towels to dry, then lightly coat all over with oil. Sprinkle evenly with salt and ground peppercorns, gently pressing to help them adhere.
Set a cast-iron griddle or large roasting pan over two burners and heat over high until hot. Carefully rub griddle lightly with oil. (If using a roasting pan, add enough oil to barely coat the bottom of the pan.) Heat until hot but not smoking, then place the tenderloin on the griddle and sear on all sides, about 3 minutes per side. Use tongs to transfer beef to a rack set in a rimmed baking sheet.
Roast until an instant-read thermometer inserted into thickest part registers 125 degrees for medium-rare, 20 to 30 minutes. Let rest 10 minutes.
Transfer tenderloin to a carving board and slice to desired thickness (about 1/2 inch is a nice size) before serving.