Combine vinegars, sugar, and peppercorns in a small saucepan and warm over low heat until sugar dissolves. Add thin sliced pears and poach for 1 minute.
Remove from heat and allow pears to steep for 1 hour. Remove pears from liquid.
Return liquid to heat and cook to reduce slightly.
Notes
I served the pears in an Orzo Salad and used the balsamic reduction in my Lemon Blackberry Vinaigrette.