For the vegetable strudel with parsley sauce, first knead the ingredients for the dough and form it into a ball. Wrap in plastic wrap and place in the refrigerator for about 1 hour.
In the meantime, peel and finely dice kohlrabi and carrots. Cut broccoli into small florets. Cut stalk into small cubes. Finely chop chervil.
Sauté vegetables in butter for about 5 minutes.
Add breadcrumbs and chervil. Season with salt and pepper. Then allow to cool.
Preheat the oven to 200 °C. Cover a baking tray with baking paper.
Roll out the dough thinly on a floured tea towel. Carefully roll out thinly by hand.
Spread the filling on the dough, leaving a border free.
Roll up with the help of the tea towel.
Place seam side down on baking sheet and bake for about 20 minutes.
Meanwhile, boil milk and thicken with sauce thickener. Add parsley, lemon juice, sugar, salt and pepper to taste.
Remove strudel from oven, portion and serve with sauce.