Separate eggs. Mix flour, milk and egg yolks. Beat the egg whites and 1 pinch of salt with the whisk of the hand mixer until stiff, fold into the flour mixture. Let the dough stand for about 15 minutes.
In the meantime cut the bacon into pieces. Clean and wash spring onions and cut into rings. Clean, halve or quarter the mushrooms.
Heat 1 tablespoon of oil in a pan (25 cm Ø). Leave 125 g bacon in it while turning for about 3 minutes. Remove bacon from the pan and let it cool down a little. Mix fried bacon and spring onions into the pancake batter.
Add 1 teaspoon butter to the pan with the bacon fat and heat again. Spread 1/4 of the dough in it. Bake the pancakes from both sides until golden brown. Fry 3 more pancakes one after the other in 1 teaspoon butter and keep warm.
Peel the onion and cut it into small pieces. Heat 1 tablespoon of oil in a frying pan. Fry the onion for 3-4 minutes, turning it over. Add 25 g bacon and leave out for about 2 minutes. Add the mushrooms and fry for about 4 minutes.
Season with salt and pepper. Remove from heat and place in a bowl. Wash parsley, shake dry, pluck leaves, chop finely and add to the mushroom mixture. Put 1-2 tbsp. mushroom mixture aside for garnishing, mix the rest of the mushroom mixture with crème fraîche, if necessary season again with salt and pepper.
Put a pancake on a plate. Spread 1/3 of the mushroom cream on it. Place a pancake on top and spread 1/3 of the mushroom cream on top again. Repeat this procedure once more and finish with a pancake.
Garnish with the mushroom mixture set aside.