Measure ingredients, white chocolate, pistachios and dried cranberries
Prepare quarter baking sheet by lining it with parchment paper
If using a double boiler, put an inch or two of water in the bottom pan and bring it to a low boil. Put pan on top and add white chocolate disks or chips.
Making sure that no water or moisture gets into the top pan or bowl holding the chocolate, stir the white chocolate with a clean, dry spatula every few minutes until the chocolate has completely melted. The white chocolate will look totally smooth with no lumps and glossy.
If using a microwave to melt the chocolate, put the chocolate in a microwave safe bowl and heat in short bursts--10 to 15 second increments--stirring in between so that the chocolate doesn't overheat and burn. White chocolate burns very easily.
Carefully, using potholders to protect your hands, pour white chocolate onto a parchment-lined quarter baking sheet.
Smooth white chocolate in an even layer using an offset spatula or a rubber spatula.
Working quickly (this is why you have your nuts and berries already measured and ready to go) sprinkle the pistachios and cranberries evenly over the white chocolate.
Using your fingers, lightly press the nuts and cranberries down into the layer of white chocolate to get good contact so you don't have any loose ingredients falling out of the bark.
Let rest for two hours until set. Or place in freezer for 30 minutes to set.
Break bark into pieces (about 16)using a bench scraper or a knife or your paws.
Package in an airtight container or in cellophone bags, if using for gifts.