How to make
Fireproof baking pan - 10″ (26 cm).
Pour some of the flour into a bowl and add the egg yolk, salt and butter. Mix with a spoon and gradually add more flour and water and continue to mix.
Transfer onto a kitchen counter and knead a soft dough. If it is sticky, add some flour. Do not knead it for long. Wrap the dough in cling film and put it in the fridge for about an hour to chill.
Meanwhile, cut the onion into very thin crescents. Heat the butter and fry the onion over low heat, until it aquires a golden color and softens - about 20 minutes.
When the dough is ready, roll it out onto a floured surface into a larger circle than the baking pan in which you will bake it, since it has walls. Grease the baking pan with a little butter and place the dough in it.
Prick the bottom of the dough in several places. Place foil over the dough and press it well. Bake for 15 minutes in an oven heated to 360°F (180°C).
Take out the baking pan and with gloves on, press down on the foil to flatten the bottom slightly. Remove the foil and place the baking pan back into the oven for another 5 minutes.
Beat the egg with the flour and milk. Season with salt and black pepper.
Remove the savory pie from the oven. Put the onion on the bottom. Pour the milk mixture over it and sprinkle generously with the Parmesan.
Place it back into the oven for another 20 minutes. Serve it hot.
The german onion pie is ready.
