Combine 1 cup white grape juice, 1/2 cup cognac, the juice of 1 lemon, 3 tablespoons superfine sugar and 1 cup water in a pitcher. Add 1 cup each halved grapes and pitted cherries, and 1 sliced peach. Chill 3 hours or overnight. Before serving, add a bottle of cold sparkling wine. Pour into flutes.
Photograph by Con Poulos