Roast Beef Tenderloin With Dried Fruit And Nut Stuffing

1. 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 port, prunes, and apricots in bowl; cover and microwave until simmering, about 2 minutes.
2. When shallot is softened, add fruit mixture, thyme, salt, and pepper; continue to cook, stirring occasionally, until mixture is thick, 1 to 2 minutes. Off heat, stir in balsamic vinegar. Transfer fruit mixture to plate. Set aside and cool to room temperature.
3. FOR THE ROAST: To butterfly roast, insert chef’s knife about 1 inch from bottom of roast and cut horizontally, stopping just before edge. Open meat like a book. Make another cut diagonally into thicker portion of roast. Open up this flap, smoothing out butterflied rectangle of meat. Season cut side of roast with kosher salt and pepper. Spread cooled stuffing mixture over interior of roast, leaving 1⁄2-inch border on all sides; distribute pecans on top of stuffing. Roll roast lengthwise and tie with 8 pieces kitchen twine evenly spaced.
4. Stir 1 tablespoon oil, 1-1⁄2 teaspoons kosher salt, and 1-1⁄2 teaspoons pepper together in small bowl. Rub roast with oil mixture and let stand at room temperature for 1 hour.
5. Adjust oven rack to middle position and heat oven to 450 degrees. Heat remaining 2 tablespoons oil in 12-inch skillet over medium-high heat until just smoking. Add beef and cook until well browned on all sides, 8 to 10 minutes total. Transfer beef to wire rack set in rimmed baking sheet and place in oven. Roast until thickest part of roast registers 120 degrees (for rare), 16 to 18 minutes, or 125 degrees (for medium-rare), 20 to 22 minutes.
6. FOR THE STILTON BUTTER: While meat roasts, combine butter ingredients in bowl. Transfer tenderloin to carving board; spread half of butter evenly over top of roast. Loosely tent roast with aluminum foil; let rest for 15 minutes. Cut roast between pieces of twine into thick slices. Remove twine and serve with remaining butter.

BUTTERFLYING, STUFFING, AND TYING A TENDERLOIN
1. Insert chef’s knife about 1 inch from bottom of roast and slowly cut horizontally, stopping just before edge. Open meat like a book.
2. Make another cut diagonally into thicker portion of roast. Open up this flap, smoothing out butterflied rectangle of meat. Butterflying the roast gives you a wide, even surface to spread the stuffing.
3. Spread filling evenly over surface, leaving 1⁄2-inch border on all sides. Press spinach leaves or pecans evenly on top of filling. Using both hands, gently but firmly roll up stuffed tenderloin.
4. Evenly space 8 pieces kitchen twine (each about 14 inches) beneath roast. Tie each strand tightly around roast, starting with ends.