1.In a small bowl, mix the dried fruit with the wine. Melt the butter in a large ovenproof skillet. Add the apple and cook over moderate heat for 3 minutes. Add the onion and cook, stirring, until softened, about 7 minutes. Add the water as the pan dries out.

2.Drain the dried fruit, reserving the wine. Stir the dried fruit into the apple and onion in the skillet and season with salt and pepper. Transfer to a plate to cool. Coarsely chop 1/2 cup of the fruit mixture and reserve it for making the sauce. Wipe out the skillet.

3.Preheat the oven to 425F. Insert a sharpening steel or the handle of a wooden spoon into the thick end of the tenderloin. Carefully push the steel through the tenderloin and roll the meat to widen the hole slightly. Stuff the tenderloin with the fruit mixture and seal the ends with toothpicks.

4.Heat the oil in the skillet. Season the meat with salt and pepper and brown it in the skillet over high heat, turning, for about 6 minutes. Transfer the skillet to the oven and roast the meat for 25 minutes. Transfer the meat to a cutting board and let rest for 5 minutes.

5.Add the reserved wine to the skillet and cook over high heat, scraping up any browned bits, until syrupy, about 2 minutes. Add the stock and cook until reduced by half, about 5 minutes. Stir in the reserved 1/2 cup of the fruit mixture and season with salt and pepper. Slice the tenderloin crosswise 1/2 inch thick and serve with the sauce.