In a heavy bottomed pan mix the sugar, white wine and lemon juice. Stir over a medium heat until the sugar has dissolved completely.
Stir in the double cram and cook over a gentle heat, stirring constantly , until the mixture thickens.
Add the rosemary then the chocolate, stirring until completely dissolved. Bring to the boil and simmer gently for about 20 minutes until dark and thick. Cool until tepid.
Pour through a sieve into 6 glasses or ramekins. Cover and refrigerate until set. Decorate each pot with a sprig of rosemary and a sprinkling of almonds if wished.