Juice the lemons until you have 100 ml of juice. Put the cream, sugar, bay leaves and lemon zest strips in a small pan and bring to the boil, stirring a few times until the sugar has dissolved.
Simmer for 2 minutes then stir in the lemon juice and return to the boil. As soon as the liquid starts to bubble up remove from the heat and pour through a sieve into a jug.
Divide equally between four glasses or ramekins. Allow to cool then chill for at least a couple of hours until set.