How to Make It
Preheat oven to 425°F with oven rack in lower third of oven. Rub roast all over with sea salt, and place roast, fat cap up, on a wire rack set inside a roasting pan. Let roast stand at room temperature while oven is preheating, about 30 minutes. (Roast may be seasoned and refrigerated, uncovered, up to overnight. Let stand 30 minutes at room temperature before proceeding.) Insert a probe thermometer in thickest part of roast.
Roast in preheated oven until meat is lightly browned, 20 to 25 minutes. Without opening oven, reduce oven temperature to 225°F. Continue roasting until internal temperature of meat registers 120°F, about 2 hours and 30 minutes for medium-rare. Transfer roast to a cutting board, and let rest 40 minutes before slicing. Sprinkle slices with sel gris, and serve with Morel Cream Gravy and carving board juices.