In a small saucepan, combine the apricots, cherries, shallot, ginger, wine, vinegar, water and sugar and bring to a boil.
Cover and cook over moderate heat until the liquid is absorbed and the fruit is softened, about 10 minutes.
Stir in the dry mustard, Dijon mustard and butter.
Simmer until the mostarda is jamlike, 2 to 3 minutes longer.
Serve the mostarda warm or at room temperature.
