Make sure to note on the gift tag to keep this tart and nutty chocolate bark refrigerated until ready to enjoy, but not longer than one month for best flavor.
Stir 1 cup pistachios and 1 cup cherries into semisweet chocolate. On large cookie sheet, spread chocolate mixture to about 1/4-inch thickness. Spoon dollops of white chocolate onto semisweet-chocolate mixture. With tip of knife, swirl chocolates together for marbled look. Sprinkle with remaining pistachios and cherries.
Refrigerate bark 1 hour or until firm. Break bark into pieces. Store in tightly sealed container in refrigerator up to 1 month. Pack in decorative boxes lined with waxed tissue paper or colored cellophane for gift giving.