Grease a tart mould with a removable base (26 cm Ø) and dust with flour. 250 g flour, 1⁄2 tsp salt, 125 g fat in pieces, 1 egg and 1-2 tbsp water first with the dough hooks of the hand mixer, then quickly knead with your hands to a smooth dough.
Roll out round (approx. 32 cm Ø) on a floured work surface. Line a mould with it, press up at the edge and cut straight. Chill for about 30 minutes.
Dice the bacon. Peel and finely dice the onion. Heat 1 tablespoon of oil in a saucepan. Fry the bacon until crispy. Fry the onion briefly. Add sauerkraut. Season with pepper and thyme and braise covered for about 10 minutes.
Cool down a little and drain well.
Cut the sausages into slices. Heat 1-2 tablespoons of oil in a frying pan. Fry the sausages until golden brown and take them out. Whisk 4 eggs and sour cream. Season with salt, pepper and nutmeg.
Sprinkle the dough base with breadcrumbs. Mix the sauerkraut with 2⁄3 egg cream and spread on the dough. Spread the sausage on top and pour the rest of the egg-cream evenly over the dough. Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for 35-40 minutes.
Wash and finely chop the parsley. Sprinkle quiche with parsley. Serve with sour cream.
Drink tip: beer, e.g. a tart Pils.