Preheat oven to 350°.
Spread the walnuts on a baking sheet and toast for 8 minutes. Let cool, then coarsely chop.
Line a baking sheet with parchment or wax paper.
In a glass bowl, heat two-thirds of the chocolate in the microwave on high for 30 seconds at a time until just melted. Stir until smooth.
Add the remaining chocolate and stir until melted.
Stir in the walnuts, cherries, blueberries, and ginger until evenly coated.
Scrape the mixture onto the prepared baking sheet and spread it into a 12 x 8 inch rectangle.
Refrigerate for 20 minutes, or until firm enough to cut.
Cut the bark into 48 pieces (6 rows by 8 rows) and transfer to a plate.
Serve cold or at room temperature.