Look for the tapered, thinner end, and tuck it under before tying up the roast. Use kitchen twine to tie the roast firmly, but not too tight. Tie in even, 1-inch intervals. OR, ask your local butcher to do it for you.
Tie your roast
If you have the time, plan to chill your tenderloin in the refrigerator uncovered overnight.
Chill overnight (optional)
Season and slather
Bring to room temperature, season, and slather the outside with softened butter.
In a large cast-iron skillet sear, undisturbed, until browned, approximately 3-4 minutes. Repeat on all remaining sides.
Preheat oven and transfer the seared beef tenderloin to a roasting pan. Transfer to the oven.
Red wine sauce
Use the same cast-iron skillet that you used to sear your roast to make the red wine sauce,
Remove the roast and allow it to rest for about 15 minutes before slicing.
Slice & Serve
Remove the cooking twine and slice.