Tarte alsacienne aux oignons

For the Pastry

• 10 oz (300 g) wheat flour
• 5 oz (150

First make the pastry. Sift the flour into a bowl, make a well in the middle and add the butter, salt and egg. Mix with your fingertips until the mixture forms a ball. Knead on a floured board until the dough is completely smooth. Roll into a ball, cover with a floured teatowel and allow to rest at room temperature for a couple of hours.

Then roll out the pastry and use it to line a wel