Heat oven to 350.

Peel the pear and slice it into six wedges. Remove the core. In a medium saucepan, bring the water, wine, and 3 tablespoons of honey to a boil. Reduce to a simmer and add the pears. Cover and cook 15 minutes, or until the pears are soft. Use a slotted spoon to transfer the pears to a cutting board. Let cool, then cut into a medium dice.

Butterfly the pork tenderloin by slicing it lengthwise 3/4 of the way through, then opening it like a book. Cover with plastic wrap and use a mallet to flatten the meat to 1/2-inch thickness.

Remove the plastic wrap and cover the pork with an even layer of diced poached pears. Repeat with the gorgonzola, walnuts, and breadcrumbs.

Roll the pork tenderloin into a cylinder, sealing the filling inside. Brush with the remaining tablespoon of honey and season with black pepper. Wrap the tenderloin with the prosciutto, slightly overlapping the slices crosswise. Use kitchen twin to tie the tenderloin together in 4 or 5 places to help it keep it's shape. Transfer to a baking sheet.

Roast pork until a meat thermometer registers 140ºF, about 40 minutes. Remove from oven and transfer to a cutting board; let rest 10-15 minutes.

To serve, cut pork tenderloin into 1/2-inch slices.