Ingredients:

100g classic 74% dark chocolate, chopped, plus extra shards to decorate (optional)

25g butter, cubed

3 large eggs, separated

2 tbsp caster sugar

2 tbsp whipping cream (optional)

Steps:

1. Put the chocolate, butter and 75ml warm water (see tip, below) in a heatproof bowl set over a pan of barely simmering water. Push the chocolate and butter gently into the warm water with a wooden spoon to help it melt, but avoid stirring too much. Once three-quarters of the butter and chocolate is melted, remove the bowl from the heat. Stir until melted, smooth and glossy. Set aside until lukewarm.
2. Working quickly, use a spatula to stir the egg yolks into the chocolate mixture, one at a time. In a separate bowl, use an electric whisk to whip the egg whites to soft peaks, then gradually add the sugar, whisking, until stiff peaks form.
3. Gently fold about a fifth of the egg whites into the chocolate mixture, then fold in the rest, being careful not to knock out the air bubbles. Pour into wine or dessert glasses, cover with cling film and chill overnight to set.
4. When ready to serve, whip the cream (if using) to soft peaks. Top each glass with a spoonful of cream and decorate with chocolate shards, if you like.

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