Heat the butter, water, sugar and salt over medium heat. When the butter is melted, add flour and beat with wooden spion until mixture comes together and forms dough. Keep stirring over low heat until dough Coat the bottom of pan.

Remove dough from pan.Let it cool slightly. Add egg gradually and mix well until the dough incorporated like thick paste.

Pour dough into the piping bag. Pipe the mixture to tray. Bake in preheated oven 180°C for 20-30 minutes. Don't not open the oven as choux ia cook. Remove from oven and transfer to cooling rack. Allow it cool.before fill

Split open the pastry. Fill with fillling. You also can poke a hole in pastry and pipe the filling inside.