Preparation

• Let the roast sit at room temperature for 30 min. Meanwhile, position a rack in the middle of the oven and heat the oven to 400°F. Put a roasting rack in a roasting pan or a heavy-duty rimmed baking sheet. (Line the pan with foil for easier clean-up, if you like.)
• Season the roast liberally with salt and pepper on all sides. Turn on the exhaust fan. Heat the oil in a large sauté pan over medium-high heat. When the oil is hot, brown the meat well on all sides, including the ends, about 4 min. per side. Transfer the meat to the roasting pan. Set aside to cool while you prepare the crust.
• In a medium bowl, combine the breadcrumbs, garlic, shallots, thyme, marjoram, 1/2 tsp. salt, and 1/4 tsp. pepper. Pour the melted butter into the breadcrumb mixture; toss to combine. Using a rubber spatula, smear the top and sides of the beef with the mustard. With your hands, lightly press the breadcrumb mixture into the mustard.
• Roast the beef until an instant-read thermometer inserted into the thickest part of the meat reads 125°F for medium rare, about 60 min. for a strip loin roast or 60 to 80 min. for a top sirloin roast, depending on its thickness. (To keep the crust from overbrowning, start checking on the roast after 30 minutes of cooking, and when the crust is golden brown, tent it with aluminum foil.)
• Meanwhile, make thehorseradish-mustard sauce.
• Remove the roast from the oven and let the meat rest for 10 to 20 min. (the meat will continue to cook as it rests) before carving, across the grain, into 1/2-inch-thick slices.

The deep berry flavors and robust tannins of a Cabernet Sauvignon or Cabernet-Merlot blend from California or Australia will pair beautifully with this roast.