1) Heat pan, add water, sugar and butter till melted and sugar dissloves.
2) Add flour, stir until dough non-stick to the pan. Remove to cool.
3) Add egg in dough one at the time until dough smooth and mixed well.
4) Used piping bag with star nozzle to shaped the puff.
5) Spray with some water to help the dough rising fast.
6) Bake till puff turned light brown. Put aside to cool.
7) Cut the puff into half and filled the filling.
Heat pan, put custard flour, water, milk and sugar, mix and stirring continuously till it becomes thick. Put aside to cool.