1. In a dry pan, lightly toast the nuts then set aside to cool.
2. Line a cookie sheet with parchment paper and set aside.
3. Melt the semi-sweet and white chocolate simultaneously in separate double boilers or one at a time in the microwave ( in a medium microwave-safe bowl, microwave the chocolate until melted, stirring after every 30 seconds to prevent overheating), while the semi-sweet chocolate is melting add the orange zest.
4. Once both chocolates are melted, pour the semi-sweet chocolate onto the prepared baking sheet and smooth out into your desired shape then drop spoonfuls of the melted white chocolate on top. Use a wooden skewer or the tip of a knife to swirl the two chocolates together until you are happy with the design.
5. Sprinkle the pistachios and cranberries over the swirled chocolate than sprinkle a little more orange zest on top and allow to cool for approximately two hours or until the chocolate is hard and can be broken into pieces to serve.