Cut the tenderloin into one-inch thick pieces across the grain. In a shallow dish, combine the vinegar and the sugar, stirring until the sugar is dissolved. Place the tenderloin in the marinade for 20-30 minutes.
Heat 4 tablespoons of the oil in a small skillet and saute the hazelnuts until golden brown. Set aside.
Heat the remaining 4 tablespoons of oil in a large skillet over medium heat. When it is hot, add the tenderloin and saute for 4 minutes on each side, until the pieces are caramelized. Set the pieces aside on a warm platter.
Deglaze the large skillet with the sherry and reduce the liquid slightly.
Add the hazelnuts, currants, and pork tenderloin and simmer for two minutes or until the meat is heated thoroughly.
Spoon the sauce over the pork tenderloin and serve.
Graland Country Day School is a private school in Denver, Colorado, serving students in preschool, kindergarten, elementary, and middle school. Founded in Denver in 1924, Graland incorporates a rich, experiential learning approach in a traditional classroom setting, emphasizing the development of globally and socially conscious leaders who excel academically.