Break chocolate into small pieces and melt in a double saucepan, over
gently simmering water (or in a bowl suspended over a saucepan of water).
As the chocolate melts, stir in the margarine, stirring until chocolate
is totally melted and completely smooth. Holding a paper case at an
angle and rotating slowly, drizzle in the chocolate, a spoonful at a
time, until the whole inside of the case is coated.
Continue with more paper cases until the chocolate is used up (should
make 8 to 10 servings). Chill the cups in the fridge for 30 minutes
or so.
Beat enough icing sugar into the cashew cream to sweeten and stiffen;
this will depend on the thickness of your cashew cream. Carefully peel
the paper cases away from the chocolate cups, then fill with the 'cream'
mixture. Garnish with a slice of fruit for that finishing touch (e.g.
kiwi, strawberry, mandarin segment).