Tip your pistachios onto an oven tray, place in the oven and roast for 10 minutes, allow to cool then roughly chop and set aside.
Lightly oil a baking tray and line with baking paper (the oil helps anchor the paper and makes it much easier to spread the melted chocolate).
Put approximately 2/3 of the chocolate in a microwave safe bowl, heat in the microwave on full power for 30 seconds, stir, then return to the microwave for 20 seconds at a time, stirring well after each blast, until the chocolate has melted.
Add the remaining chocolate, stir until smooth then stir through the Moccona instant coffee.
Pour the melted chocolate into the baking tray, spread to a smooth even layer with a spatula or pallet knife.
Immediately strew with pistachios and a final sprinkle of salt. Leave at room temperature until completely set, break into artistic shards and store in an airtight container.
Perfect for when guests drop in or lovely with coffee at the end of a great dinner party.