Lightly break up the meringue into chunky pieces. Whisk the cream lightly until leaving a trail, add the lemon rind and juice and lemon curd to the cream and lastly fold in the meringue and lemon balm. Try not to over crush the meringues.
Spoon the lemon meringue mixture into the loaf tin and cover with cling film then freeze for at least 6 hours. If the ice cream has been in the freezer overnight or longer it has to be brought to room temperature for about 10-15 minutes before turning out on to a plate.
To serve mix the remaining lemon curd with the scooped out seeds from the passion fruit. Remove the ice cream from the loaf tin, invert it onto a board and remove the cling film. Dip a sharp knife in boiling water and slice the loaf into fairly thick slices.
Serve on a plate with a spoonful of lemon and passion fruit on top and decorate with sprigs of lemon balm.