Preheat oven to 200 degrees. Grease a baking pan and keep ready.
Heat butter in a saucepan. Add the onion and saute till soft.
Add the flour and saute till it change color.
Add the chicken stock and cook till the mixture thickens.
Keep whisking so that there are no lumps. Add the chicken and briefly cook for a couple of minutes. Adjust the seasoning and switch off.
Take one puff pastry square, spread some chicken mixture, cover with another puff pastry square. Press the sides to stick them.
Transfer to the baking tray. Repeat for the remaining puff pastry squares, till you make a total of 7.
Bake for 20 minutes. Cool slightly. Serve warm and enjoy!
Notes
To make chicken stock if not available, melt one cube of Maggi chicken stock in water and use. You can substitute the stock with milk or part cream and water. You can add some vegetables to the filling to make it more wholesome.