In a non-reactive saucepan, combine vinegars and simmer. Reduce by 60 to 70 percent until a syrupy consistency is achieved. Keep in mind that the syrup will thicken as it cools. In a bowl, mix julienned pears with lime juice and season with pepper. Using a sushi mat lay out one or two slices of prosciutto. Lay the pear pieces across the bottom of the prosciutto. Roll very tightly.
Drizzle some vinegar syrup on a plate in a zigzag pattern. Slice rolls like sushi and garnish with chives and cracked peppercorns.