Pour water into a 9-cup ring mold to a depth of 1/4-inch; freeze until firm. Arrange orange slices, lemon slices, and maraschino cherries on top of frozen layer. Pour 3/4 cup cold water over top, and freeze. Continue adding 3/4 cup cold water and freezing after each addition until mold is filled and completely frozen.
To serve, unmold ice ring, and place in a punch bowl. Combine Sauterne, Cognac, lemon juice, Triple Sec, and grenadine. Pour over ice ring. Gradually stir in mineral water. Garnish with mint sprigs, if desired.