1. Preheat the oven to 375°. Set a rack in a large, deep roasting
pan and place the beef roast on the rack.
2. In a small bowl, blend the horseradish with the salt, Dijon
mustard, chopped parsley, ground pepper, sugar and sherry
vinegar to form a paste. Slather the paste all over the top and sides
of the meat. Roast in the lower third of the oven for about 2
hours, until an instant-read thermometer inserted in the center
of the roast registers 125°. Transfer the roast to a cutting board
and let rest for at least 20 minutes.
3. Discard the string and thinly slice the roast beef across the
grain. Transfer the meat to a platter and serve.
—Jessica Applestone and Joshua Applestone
MAKE AHEAD The unsliced roast beef can be refrigerated for
up to 3 days. The sliced roast beef can be wrapped in plastic and
SERVE WITH Mashed potatoes.