If using an ice-cream maker place the bowl in the freezer for 24 hours before needed.
Place the lemon juice in the bowl and add the icing sugar.
Whisk until the sugar is dissolved.
Measure the elderflower cordial in the measuring jug and top up with cold water to 400ml.
Add the sweetened lemon juice and whisk everything together.
Turn the ice-cream maker on to set the paddle going and slowly pour in the liquid.
Churn until a sorbet consistency has been reached.
Immediately transfer to an ice-cream pot or freezable lidded container and place in the freezer.
Allow to completely freeze before serving.
Alternatively, if you haven’t got an ice cream maker, pour the liquid into the freezable container, cover and place in the freezer for an hour or until the mixture starts to crystallise.
Remove from the freezer and beat until smooth.
Return to the freezer and repeat this process every hour until the right consistency has been reached.