Put flour, butter in flakes, 1 pinch of salt and 1 egg in a bowl. Knead first with the dough hooks of the hand mixer, then with your hands to a smooth dough. Wrap in foil and chill for about 30 minutes
Clean and wash the red cabbage. Cut cabbage into quarters, remove stalk. Cut cabbage into slices. Caramelise sugar and 3 tbsp. water in a pot until light brown. Pour on red wine, add red cabbage slices and simmer at low heat for 10-15 minutes. Season with salt and pepper. Remove from the stock and drain
In the meantime, clean, wash and halve the pumpkin. Remove seeds. Cut pumpkin into small cubes. Peel and halve onions and cut into strips. Heat oil in a pan. Fry the onions for about 3 minutes. Add pumpkin cubes and steam for 3-4 minutes. Season to taste with salt, pepper and nutmeg
Roll out the dough into a circle (approx. 30 cm Ø) on a slightly floured work surface. Pour into a greased, flour-dusted mould (26 cm Ø). Press down the rim. Line the pastry base with baking paper and spread dried peas on top. Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 10 minutes until completely dry.
Stir the sour cream and 3 eggs. Season well with salt and pepper. Take the dough out of the oven. Remove baking paper and dried peas. Spread red cabbage and pumpkin-onion mixture on the bottom. Pour the sour cream mixture over it. Chop pumpkin seeds and sprinkle over it. Bake in the oven at the same temperature for about 45 minutes