To grill peaches: Slice ripe peaches in half. Remove pit. Place peach half, cut side down, onto grill over indirect heat. Grill until grill marks appear and peaches begin to soften. Remove from grill and cool.
To make grilled peach puree: Remove skin from cooled grilled peaches. Discard skins. In a blender, puree peaches. Store unused puree in refrigerator or freeze for future use.
In a 16 ounces wine glass place 2 tablespoons of grilled peach puree. Top with 12 ounces of CK Mondavi Moscato. Stir gently to combine. Top with sparkling water. Gently stir. Add a few ice cubes. Make a diagonal slice in the peach slice and place on side of glass for garnish.