In a 12- to 14-inch frying pan, combine orange peel, orange juice, wine, 3/4 cup sugar, cardamom, coriander, and ginger. Boil over high heat until reduced to about 1 cup, about 20 minutes.
Meanwhile, rinse plums and cut into chunks; discard pits.
Add plums to reduced sauce. Simmer rapidly, stirring often, until fruit is very soft and mixture is reduced to about 3 cups, about 25 minutes. Taste and add additional sugar if desired, then simmer 2 to 3 minutes more.