How to Make It
Preheat the oven to 350°. Spread the pistachios on a rimmed baking sheet and toast for about 7 minutes, or until fragrant. Let cool.
Line 2 large baking sheets with parchment paper and place them in the freezer. In a heavy medium saucepan, combine the cream with the sugar, corn syrup and butter and bring to a boil. Stir just until the sugar dissolves. Cook over moderately low heat, without stirring, until the caramel reaches 240° to 244° on a candy thermometer; this can take up to 45 minutes.
Fill the sink with 1 inch of cold water. Add the 3 tablespoons of water to the caramel and boil over high heat for 5 minutes, stirring occasionally. Briefly dip the saucepan in the cold water to stop the cooking, then let the caramel cool to 200°.
Stir the pistachios and dried cherries into the caramel. Spoon scant tablespoons of the caramel onto the chilled baking sheets and let cool completely, at least I hour.
In a medium bowl, melt three-quarters of the chocolate in a microwave. Stir in the remaining chocolate until melted. Dip the bottom of each caramel into the chocolate and return to the baking sheets. Refrigerate for 10 minutes to set the chocolate.