Place water in the bottom of a double boiler and bring to a boil. (If you don’t have a double boiler, place a heatproof bowl over a saucepan of gently simmering water, making sure the bottom of the bowl isn’t touching the water.) Meanwhile, chop the chocolate into large chunks. Set aside 1 tablespoon each of the pistachios, cranberries, and coconut. Place a Silpat mat or sheet of parchment paper on a rimmed baking sheet; set aside.
Melt the chocolate in the top of the double boiler, stirring occasionally. Once the chocolate is completely melted and smooth, turn off the heat and stir in the nuts, cherries and coconut. Pour the chocolate mixture onto the prepared baking sheet, spreading out the mixture with a spatula to approximately an 8-by-10-inch rectangle. Sprinkle the reserved nuts, cranberries and coconut evenly on top. Sprinkle the salt over the chocolate.
Transfer the baking sheet to the freezer and freeze for 1 hour, until completely firm. Using clean hands, break the chocolate into chunks and enjoy, or transfer to a sealed container. Store in the freezer for best results.