Line a baking sheet with baking parchment.

In a medium heatproof or Pyrex bowl, break 200g of the dark chocolate into small evenly sized pieces.

Half fill a small saucepan with water, and place over a medium heat.

Bring the water to a simmer and lower the heat.

Place the bowl over the saucepan and ensure the base of the bowl is not touching the water.

Allow the heat to gently melt the chocolate, stirring occasionally.

Test the chocolate temperature using a chocolate/ candy thermometer; the chocolate should be between 48-49ºC.

Remove the chocolate from the saucepan and wrap the bottom of the bowl in a tea towel. This will allow the chocolate to cool down gradually.

Add the remaining chocolate and allow it to melt gently, stirring occasionally. By adding the chocolate at this point, it helps to give the cocoa butter crystals good. Also the stirring helps to give good crystallisation.

Test the chocolate temperature, and when it has reached 28-29ºC, place the bowl back over the saucepan and gently bring the temperature back to 31-32ºC. Do not allow the chocolate to overheat. The chocolate is now ready to work with.

Working quickly, pour the tempered chocolate onto the baking sheet and holding at the corners gently tilt and shake the sheet to even out the chocolate.

Scatter fudge pieces, chocolate chunks and sultanas all over the chocolate, press down gently on the toppings to secure them into the bark.

Scrape out any leftover chocolate in the bowl with a spatula and drizzle over the top of the bark.

Allow the bark to cool and firm up for at least an hour.

Lift off the baking parchment and break into shards.