1. If your beef tenderloin has any loose ends, be sure to tie them up with butcher's twine.
2. After it is tied, put the tenderloin on a wire rack that will fit into a baking dish.
3. Lightly salt the tenderloin on all surfaces.
LET THE TENDERLOIN CURE
4. Allow the tenderloin to cure uncovered in the refigerator for 8 - 24 hours.
5. Insert a digital thermometer into the center of the tenderloin.
6. Roast the beef tenderloin until 110° internal temperature is reached
7. Rest the tenderlion for 10 minutes.
8. During the resting time, heat a cast iron skillet over medium heat until it reaches 600°.
9. Add oil to the skillet.
10. Sear the beef tenderloin on all sides for 45 seconds and 30 seconds on each end.
11. Rest it again for 10 minutes.
12. Slice into two inch slices.
13. Serve with horseradish sauce and sides of your choice.