Prepare flour, water, 3 tbsp oil and a tsp salt to a smooth dough. Brush with 1 tbsp oil, rest in refrigerator for one night.
Roll out strudel dough on floured kitchen towel. Roll out paper-thin over back of hand. Place on dish hangl, cut thick edges into small pieces.
You should get a rectangle of 60×50 cm.
Season the vegetables with salt. Stir crème fraîche and egg yolk, mix with vegetables. Cover dough with vegetables, leaving a 5-6 cm border all around. Fold edges of dough over filling in the middle. Roll up loosely from the long side using the cloth and place on a baking sheet lined with parchment paper. Brush with remaining oil.
Bake in oven heated to 250 °C for about 10 minutes until golden brown. Cut strudel into not too narrow slices with a sharp kitchen knife.
Serve: Serve hot or cooled. Serve with chive cream.
Preparation Tip:
As an alternative to the fresh chives, you can also use the freeze-dried.