Cut the sorrel leaves into fine strips, then sweat in 20 g butter and set aside. Cut the mushrooms into slices and sauté in 20 g butter, deglaze with white wine (alternative: vegetable broth - possibly white balsamic vinegar, but I haven`t tried it yet) and reduce. Season with salt and pepper and remove from the stove. Mix 1 teaspoon of the flour with the cream and add to the mushrooms, bring to the boil while stirring for about 1 minute.
Mix the eggs, milk and the remaining flour, season with salt and pepper. Heat the butter in a pan, add half of the egg mixture and bake, the surface must not become too firm!
The next step is to put half of the sorrel on it - on the not yet solid surface - and bake it completely. Spread half of the mushroom filling on top and fold the pancake over. Prepare the second pancake in the same way.