1/2 cup water
1/2 cup Sugar
1 2-inch piece of fresh ginger (peeled and chopped (1/4 cup))
2 tablespoons mild honey
1 tablespoon fresh lemon juice
1 pound ripe white nectarines (pitted, peeled, and roughly chopped or puréed (2 cups))
2 tablespoons candied ginger purée (optional)
1 1/2 cups plain yogurt (not nonfat) (preferably Russian or Greek)
1/2 cup finely chopped crystallized ginger ((if not using purée))