Pile the flour on the work surface, make a well in the middle and add an egg. Rub ice-cold butter into the well and add a pinch of salt. Quickly knead all ingredients into a dough. Wrap the dough in cling film and chill for 30 minutes.
Fry the diced bacon in a little butter. Cut the leek and add to the pan with the onion cubes with the bacon. Meanwhile, roll out the shortcrust pastry with a rolling pin on the floured work surface. Put the rolled out dough in a quiche dish and press firmly. Mix eggs and cream together with pepper, leek, onions and bacon in a bowl and then pour onto the dough. Place in the preheated oven (180 ° C, top / bottom heat) for 35 minutes.