Wash and zest the lime. Break the white chocolate into small pieces and place in a heatproof bowl. Zest the lime into the bowl. Heat the cream until almost boiling and then add to the chocolate. Mix until all of the chocolate has melted and then stir in the ground almonds.
Chill in the fridge for 1 hour.
Blitz the pistachio in a food processor to make a powder. Use a teaspoon to scoop small amounts of the truffle mixture from the bowl. Roll into 1cm balls and roll through the ground pistachio. Chill in the fridge until ready to serve.
«This truffle mixture will not hold up well when not kept in the fridge. If you need something firmer, use 2 thirds chocolate to 1 third double cream.»