1.Combine sugar and the water in a small saucepan. Stir over low heat until sugar dissolves. Add lemongrass. Simmer for 5 minutes.
2.Place papaya in syrup. Simmer for 5 minutes or until papaya is almost tender. Remove from heat and cool.
3.In a small bowl, using an electric mixer, beat cream, icing sugar and vanilla until soft peaks form.
4.Spoon half the cream mixture among serving glasses. Top with half the meringue and half the papaya in syrup. Repeat layers. Top with extra papaya and sprinkle with zest, to serve.
Papaya can be replaced by pawpaw. They are very similar in texture and taste, but pawpaw flesh is usually a lighter orange in colour and a little less sweet.