Preheat oven to 180°C -350°F.
Roughly chop the pistachio nuts, macadamia nuts and peanuts. Add the nuts to a baking tray lined with parchment paper. Spread them out to achieve an even roast and roast them in the oven for 6 minutes or until lightly golden brown. Allow to cool down.
In the meantime, place the digestive biscuits into a mixing bowl and crush them with your hands into different-sized pieces.
Add in the marshmallows as well as the cooled roasted nuts and mix it all together.
For the chocolate, place a large saucepan onto your stovetop and add in both chocolates, butter and golden syrup. Place over medium-low heat and gently stir the ingredients regularly, just until everything has melted together. Remove from the stovetop.
Add the dry mixture to the chocolate, half at a time. Mix the dry mixture through until everything is coated well. Add in the remaining dry mixture.
Pour the mixture into a 20cm x 20cm baking dish lined with parchment paper. Firmly push down the mixture to avoid any air bubbles and for the mixture to be evenly spread out. At this point, for an optional addition, you can sprinkle over some chopped nuts for a nice layer on the top. Place in the fridge from anywhere between 2 to 24 hours to set.
To serve, remove the rocky road from the fridge and allow it to sit for 10 minutes. Remove it from the tray, discard the parchment paper and cut it into 16 even-sized pieces. To do this slice into in half, then each half in half again to get 4 even-sized rectangles. Rotate 90 degrees and repeat the process and serve. Dig in.