1.Put the carrot, celery, wombok, chicken, bean sprouts, lemon juice, fish sauce and sugar into a medium bowl; mix them together well with a wooden spoon or tongs.
2.Put one sheet of rice paper into a medium bowl of warm water; leave until it is just soft. Lift the sheet from the water carefully; place it on a board covered with a clean tea towel, with a corner of the rice paper sheet pointing towards you.
3.Put 1 rounded tablespoon of filling mixture horizontally in the centre of the rice paper sheet; put one mint leaf on top. Hold the corner of the sheet facing you; fold it over the filling. Roll the sheet to cover the filling; fold in the sides of the sheet. Continue rolling the sheet to enclose the filling. Do this with the rest of the rice paper sheets, filling mixture and mint leaves.
You can make the rolls up to 3 hours before the party. Put them on a tray, in a single layer. Cover with a slightly damp (not wet) tea towel and keep them in the fridge.Note