Put the sweetener and salt in a small saucepan with 200ml water. Over a high heat, bring the mixture to a simmer. Put the chocolate in a heatproof bowl and pour over half the hot liquid. Whizz with a stick blender to emulsify, then add the rest of the liquid and whizz again until glossy.

Add the olive oil and whizz again, then allow the ganache to cool to room temperature before refrigerating for 1 hour.

Use a teaspoon to scoop out 40 pieces of ganache. Scatter the cocoa powder over a high-sided tray and toss the truffles through to coat. Allow the truffles to fully set in the cocoa powder for 5 minutes, then gently shake in a sieve to release any loose powder.

The truffles will keep (chilled) for 5 days in an airtight container. Take them to someone’s house as a gift, or let them come to room temperature for 10 minutes, then enjoy.