Line a pudding bowl (or a deep regular bowl) with cling wrap, make sure the sides and base are completely covered and you leave cling wrap overhanging to help remove the Rocky Road Christmas Pudding once it has set.
Assemble your ingredients on a work bench so they are in easy reach.
Break the milk chocolate into squares and place it into a microwave safe bowl. Cook for 30 second spurts until the chocolate has just melted.
Add the marshmallows, cashews, pretzels and dried cranberries to the bowl with the melted chocolate and quickly mix together with a large metal spoon until all of the ingredients are coated with chocolate.
Pour the mixture into your prepared pudding bowl and gently push down and smooth the surface. Place the Rocky Road pudding into the fridge to set, this should only take a couple of hours.
Carefully remove the set pudding from the bowl, remove the cling wrap and turn upside down onto a serving plate - dome side on top.
Melt the white chocolate and pour over the top of the Rocky Road pudding before adding the Jaffa and mint leaves to decorate.
Refrigerate until ready to serve.