Put the cream and sugar into a large pan and slowly bring to the boil, stirring constantly. Continue to boil gently for a couple more minutes, being careful not to let the cream boil up and over the edge of your pan.
Remove from the heat and add the lemon juice (I strain my juice to remove any bits). Stir together until well combined and leave to cool for 5 minutes.
Pour into individual serving dishes and refrigerate until thick.
Serve with shortbread.
Notes
Serve with fresh raspberries or sugar frosted red currants to help cut through the richness of the dessert.