Place three-quarters of the dark chocolate in a bowl over a pot of gently simmering water.
Stir occasionally until the chocolate has melted, then remove from the heat.
Add the remaining dark chocolate and stir until melted.
Melt the caramel chocolate in the same way.
Pour the dark chocolate onto the baking tray and spread into a thin layer. Working quickly, dot the caramel chocolate onto the dark chocolate and use a skewer to swirl the two chocolates together and create patterns.
Sprinkle the Montagu Fruit Cubes onto the chocolate.
Set the chocolate bark aside to cool and harden.
Once set break or cut into pieces and store in an airtight container in a cool place.