Horseradish and Dijon mustard add a bit of "heat" to these honey-coated peach halves.
Whisk together first 3 ingredients. Brush half of honey mixture evenly over cut sides of peaches.
Coat a cold cooking grate with cooking spray, and place on grill over medium heat (300° to 350°). Arrange peach halves, cut sides up, on grate; grill, covered with grill lid, 3 minutes on each side or until tender and golden. Remove from grill, and brush cut sides of peaches evenly with remaining honey mixture.