Knead flour, 125 g butter, 1 egg, salt and chill for 1 hour. Clean and wash the leek and cut into rings. Melt 50 g butter in a pot and braise the leek in it for about 20 minutes at low heat. Season leek with salt and pepper and let it cool down. Grate the Gouda.
Whisk cream and eggs and season with salt, pepper and nutmeg. Stir in Gouda. Fold the leek into the egg mixture. Grease a tart mould (24 cm Ø) and dust with flour. Roll out the dough (28 cm Ø), place it in the tin, pressing the edges. Prick the base several times. Pre-bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 15 minutes and let cool down. Pour the egg mixture onto the cooled base and bake in the oven at the same temperature for approx. 30 minutes. Whisk the egg yolks with 1 tablespoon of water.
Roll out the dough (28 cm Ø), place it in the tin, pressing the edges. Prick the base several times. Pre-bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 15 minutes and let cool down. Pour the egg mixture onto the cooled base and bake in the oven at the same temperature for approx. 30 minutes. Whisk the egg yolks with 1 tablespoon of water. Spread the quiche with it and bake for another 10-15 minutes
20 minutes waiting time