01 -
Remove roast from fridge 2 hours before cooking. Pat dry and season generously with salt, including sides and ribs. Place in roasting pan with ribs down and fat cap up.
02 -
Whisk together heavy cream, sour cream, horseradish, black pepper, salt, and cayenne in a medium bowl until smooth. Cover and refrigerate until serving.
03 -
Arrange rack in middle position and heat oven to 500°F.
04 -
Place roast in oven for 15 minutes. Expect smoke - use ventilation and open windows as needed.
05 -
Reduce temperature to 325°F and cook for about 13 minutes per pound (1.5-2 hours total) until internal temperature reaches 115°F for rare or 120-130°F for medium.
06 -
Remove from oven, transfer to cutting board, cover loosely with foil and let rest 30 minutes.
07 -
Remove twine or cut meat from bones. Slice crosswise into 1/2-inch pieces. Serve with horseradish cream sauce.