Step 1

Break the dark chocolate into pieces and melt in short blasts in the microwave, or in a heatproof bowl over a pan of just simmering water, stirring frequently. Pour it onto a tray lined with baking parchment or foil.

Step 2

Now break the milk chocolate into pieces and melt in the same way. Repeat with the white chocolate, then drizzle them both over the dark chocolate before it sets.

Step 3

Shake the tray gently to level the mixture then leave to set somewhere cool. Chop into shards.