Grate the lemon to get the zest then squeeze it to get the juice.

Combine the lemon zest and the sugar in a food processor’s container.

Process until zest is very fine.

Stir together the zest mixture and milk in a medium bowl until the sugar dissolves.

Stir in the lemon juice.

Whip the double cream in a separate bowl until stiff but not grainy.

Fold the whipped cream gently into the lemon mixture until well blended.

Pour the mixture into a 9x5 in (23x13cm) loaf tin, and then cover with cling film.

Freeze for 3 hours, or until firm.