Easy, decadent and impressive. The meat can be seasoned and refrigerated, wrapped in plastic, for up to 24 hours.

Just bring it to room temperature before roasting.

Put beef on a sheet of plastic wrap; rub with oil.

Sprinkle with salt; rub with mustard, then season with pepper, rosemary, and thyme. Wrap in plastic wrap; let sit at room temperature for 1 hour.



Heat oven to 425˚. Place beef on a rack on a rimmed baking sheet.

Roast until an instant-read thermometer inserted into thickest end reads 115˚, about 35 minutes.

Switch oven to broiler setting; broil until crusty, 5–10 minutes. (A thermometer inserted into thickest end should read 125˚.)

Let roast rest on a cutting board for 30 minutes. Meanwhile, combine sour cream and horseradish in a bowl to make a sauce.

Thinly slice beef and serve with sauce.