Preheat the oven to 425°F. Trim the beef tenderloin of any excess fat if necessary.
Season the beef by rubbing the oregano leaves, salt, and pepper all over.
Place the meat in a roasting pan and cook for 40-55 minutes depending on the thickness and desired doneness (keep in mind that the internal temperature will rise a few degrees while it rests).
Remove the roast from the pan, cover it loosely with foil, and let it rest for at least 15 minutes.
Cut the roast into 1-inch thick slices. Season with additional salt if desired. Serve with your favorite side and enjoy!