Preheat oven to 200°C and line a 23x33cm Swiss roll tin with greased baking paper.
Whisk egg whites on full speed until stiff then gradually whisk in the sugar until glossy.
Spread mixture into tin, sprinkle with nuts, and bake at 200°C for 8 minutes.
Lower oven to 160°C and bake for 15 minutes more until firm.
Invert meringue onto clean paper, peel off backing, and cool for 10 minutes.
Whisk butter and sugar for curd, then stir in egg yolks, lemon zest, and juice.
Thicken curd over simmering water for 10 minutes then reserve 100g for the filling.
Fold reserved curd into whipped cream and spread over the cooled meringue.
Score the edge and roll the meringue tightly using the paper to assist.
Dust with icing sugar and decorate before serving.