Line a baking sheet with parchment paper and set aside.
Melt the chocolate over a double boiler (or in 30-second intervals in the microwave on 50% power, stirring after each interval).
Spread the chocolate mixture onto the prepared pan in an even layer and sprinkle the pistachios and cranberries over the top. Gently push the pistachios and cranberries into the chocolate.
Refrigerate 20-30 minutes, or until set.
Break the bark into pieces. Store in an airtight container in the refrigerator.