Melt the chocolate

• Melt two thirds of the milk chocolate in a bowl over a saucepan of simmering water.
• Off the heat, stir in the remaining chocolate until smooth and glossy.

Line the mould

• Brush the mould with tahini so the chocolate releases easily.
• Pour in the melted chocolate and coat the base and sides evenly.
• Chill until the shell is set.

Toast the kataifi

• Melt the butter in a frying pan.
• Add the shredded kataifi and toast over medium heat, stirring, until deep golden and crisp.
• Let it cool slightly.

Make the pistachio filling

• Mix the toasted kataifi with the pistachio butter and crushed pistachios.
• Stir until you get a thick, spreadable cream.

Fill and seal

• Spoon the pistachio knafeh filling into the set chocolate shells and level it.
• Pour over the remaining melted chocolate to seal the bars.
• Tap the mould to release air bubbles.

Chill and finish

• Chill until fully firm, then unmould the bars.
• Sprinkle with flaky sea salt and extra crushed pistachios.