Peel and wash the potatoes and cook them in boiling water for 20 minutes. Drain (collect the cooking water) and let it cool down a little. Warm up milk, dissolve yeast in it. Mix flour and salt, put into a bowl.
Press a depression in the middle. Add the yeast mixture, dust with a little flour and leave to rise covered in a warm place for 15 minutes. Press the potatoes through a potato ricer or mash them with a fork.
Mix with 100 millilitres of potato water. Add to the pre-dough and knead to a smooth dough using the dough hooks of the hand mixer. Leave to rise for another 30 minutes. In the meantime, clean, wash and cut the leek into pieces.
Cut the bacon into strips and drain in a hot pan. Add leek and stew for five minutes. Whisk milk and eggs. Season with salt, pepper and nutmeg. Press the dough with floured hands into a springform pan (26 cm Ø) lined with baking paper, raising a four centimetre high rim.
Spread leek and bacon vegetables over it. Add egg milk and bake in the preheated oven (electric: 200 °C/ gas: level 3) for 45 minutes. Wash parsley, dab dry and chop. Sprinkle over the leek and bacon cake.
Makes 12 pieces.