Grease and line a 20cm square tin with nonstick baking paper.
Melt the chocolate in a heatproof bowl set over a pan of barely simmering water (don’t let the water touch the bottom of the bowl); stir until smooth, then remove from the heat.
Put the ginger, marshmallows and unchopped fruit and nut mix in a mixing bowl and pour in the chocolate.
Mix with a wooden spoon until just combined.
Pour into the prepared tin and sprinkle over the chopped fruit and nuts to finish.
Chill in the fridge for 2 hrs to set, then use a warm knife to cut into 16 squares.
