INSTRUCTIONS
1
Generously season tenderloin with salt and pepper. Transfer to a wire rack set in a foil-lined rimmed baking sheet and refrigerate uncovered, at least 4 hours or overnight.
2
Preheat oven to 225°F. Place baking sheet with rack and tenderloin in oven and roast to an internal temperature of 120-125°F, using a good instant-read meat thermometer (approximately 2-3 hours). Remove from oven and set aside at room temperature, 15 minutes.
3
About 15 minutes prior to serving, add butter to a medium heat pan and swirl, raising heat to high until butter starts to foam and then stops. Let butter cook until a light nutty brown, then add the tenderloin, shallot, and thyme
4
Cook, turning occasionally and spooning hot butter and aromatics over roast, until meat is well browned on all sides and internal temperature registers 125°F for rare or 130°F for medium-rare, about 1-2 minutes.
5
Transfer tenderloin to a cutting board and allow to rest for 5 minutes before slicing. Sprinkle with finishing salt before serving.