Lemon posset

1. Heat the cream and sugar gently in a large pan. 2. When the sugar has dissolved bring the mixture to the boil, stirring all the while. 3. Add the lemon juice and rind and reduce to a medium heat. Stir constantly until it thickens. 4. Pour the mixture into 4 bowls or glasses and leave to cool. Then, put in the fridge until they are just set. 5. Serve.