Melt the chocolate in a heatproof
bowl over a pan of simmering
water, making sure the bowl
doesn’t directly touch the water.
Once melted, allow it to cool for
5-10 mins, then stir in the yogurt.
Whisk the egg whites until stiff,
then whisk in the sugar and beat
until stiff again. Fold the whites into
the chocolate mix – loosen the
mixture first with a spoonful of egg
white, then carefully fold in the rest,
keeping as much air as possible.
Put berries into small glasses
or ramekins, then divide mousse
on top. Chill in the fridge until set.