Preheat the oven to 150°C.
Whisk egg whites to soft peaks.
Gradually whisk in sugar until soft peaks return and spoon into a piping bag.
Draw four 20cm circles on baking parchment and place on a baking sheet.
Pipe meringue in spirals starting from the centre of each circle.
Bake for 20 minutes.
Turn off the oven and leave meringues inside for at least two hours to crisp.
Combine lemon zest, juice, butter, and sugar in a bowl over simmering water.
Whisk until sugar dissolves, then beat in eggs until the mixture thickens.
Remove from heat and cool completely.
Whisk double cream to soft peaks and fold in the cooled lemon curd.
Transfer the mixture to a piping bag with a 1.5cm opening.
Place the first meringue disc on a serving plate.
Pipe a spiral of lemon cream to cover the disc.
Top with another meringue disc and more cream.
Repeat layers, ending with the final meringue disc on top.
Decorate with fruit and serve.