THE Dish: Doc Willoughby's roast beef tenderloin Chef and cookbook author, Doc Willoughby is just as comfortable in "America's Test Kitchen" as he is in a classroom. He brought his ultimate dish, Roast Beef Tenderloin with Dried Fruit and Nut Stuffing, to "CBS This Morning: Saturday. For Doc, journalism and cooking have turned out to be a great combination. As executive editor of "America's Test Kitchen" cookbooks, Doc helps aspiring cooks on a local and national level (and in Canada, too!) discover the very best flavors in America's favorite dishes. The Harvard grad, who has a degree in English, was the executive editor of "Cook's Illustrated" when the magazine was founded in 1993, according to his official biography. In 2001, he moved to New York to take the job of executive editor at Gourmet magazine, a position he held until the fall of 2009. In February of 2010, he returned to "America's Test Kitchen," where he landed the title of executive editor for magazines. Doc, whose real name is John (Doc is a moniker that stuck with him from his Harvard days) is also the co-author, with Chef Chris Schlesinger, of nine cookbooks, including the award-winning "The Thrill of the Grill" and "How to Cook Meat." Doc also dabbles in the wonderful world of food and travel with his "Power Ingredients" column for The New York Times dining section. He's also on the advisory board of "Chop Chop," a magazine covering healthy cooking for children. The Chateaubriand is a cut taken from the center of the tenderloin. It should be an even thickness from end to end, without any portion of the butt end attached. The stuffing can be made a day in advance, but it must be microwaved to just room temperature before being stuffed into the roast. The roast can be stuffed, rolled, and tied the day before cooking. When carving the roast, the kitchen twine performs two duties. First, and more important, it keeps the roast intact while carving. Second, it provides a good guideline for carving the roast-simply cut the meat into thick slices between each piece of twine. If serving a crowd, this recipe can be doubled to make two roasts. Follow the recipe as directed, searing the roasts one after another, cleaning the pan and adding new oil after searing the first roast. Stuffing 2 teaspoons olive oil 1 large shallot , minced (about 3 tablespoons) 1/4 cup chopped prunes 1/4 cup dried chopped apricots (unsulfured) 2/3 cup ruby port 1/2 teaspoon minced fresh thyme leaves 1/4 teaspoon table salt 1/8 teaspoon ground black pepper 2 tablespoons balsamic vinegar Beef Roast 1 beef tenderloin center-cut Chateaubriand , 2 to 3 pounds, trimmed of fat and silver skin Kosher salt and ground black pepper 2 tablespoons toasted pecans , chopped 3 tablespoons olive oil Stilton Butter 1 ounce Stilton cheese, crumbled 3 tablespoons unsalted butter, softened 1/8 teaspoon table salt 1 tablespoon chopped fresh parsley leaves FOR THE STUFFING: Heat oil in medium saucepan over medium heat until shimmering. Add shallot and cook, stirring occasionally, until softened and golden brown, 2 to 3 minutes. Meanwhile, combine prunes, apricots, and port in microwave-safe bowl; cover with plastic and microwave on high until simmering, about 2 minutes. Set aside until needed. When shallot is softened, add dried fruit/port mixture, thyme, salt, and pepper; continue to cook, stirring occasionally, until mixture is thick, 1 to 2 minutes. Remove pan from heat and stir in balsamic vinegar. Transfer dried fruit mixture to plate. Set aside and cool to room temperature. FOR THE ROAST: Following illustrations 1 and 2, butterfly roast. Season cut side of roast liberally with salt and pepper. Following illustration 3, spread cooled stuffing mixture in an even layer over interior of roast, leaving 1/2-inch border on all sides. Sprinkle pecans in an even layer on top of stuffing. Following illustrations 4 and 5, roll and tie beef roast. In small bowl, stir together 1 tablespoon olive oil, 1 1/2 teaspoons salt, and 1 1/2 teaspoons pepper. Rub exterior of roast with oil mixture. Let roast stand at room temperature for 1 hour. Adjust oven rack to middle position; heat oven to 450 degrees. Heat remaining 2 tablespoons olive oil in 12-inch skillet over medium-high heat until smoking. Add beef to pan and cook until well browned on all sides, 8 to 10 minutes total. Transfer beef to rimmed baking sheet and place in oven. Roast until instant-read thermometer inserted into thickest part of roast registers 120 degrees for rare, 16 to 18 minutes, or 125 degrees for medium-rare, 20 to 22 minutes. FOR THE BUTTER: While meat roasts, stir all ingredients together in a small bowl until combined. Transfer tenderloin to cutting board; spread half of butter evenly over top of roast. Loosely tent roast with foil; let rest for 15 minutes. Slice roast between pieces of twine into thick slices. Remove twine from individual slices and serve with remaining butter passed separately. For more of Doc's recipes, go to Page 2.