Strain the flour into a container. Add the skim milk and whisk until smooth. Add the eggs and salt and whisk the dough until it is smooth. Dissolve the butter in a frying pan and add. Cut the chives with scissors into rolls to the dough. Let the dough rest for half an hour before baking.
To prepare the filling, remove the skin from the ascalon onion and chop finely. Dissolve half of the butter in a small pan and let the onion brown in it. Add the flour and cook briefly, stirring constantly. Add the cow’s milk. Bring the sauce to a boil while stirring and simmer on a low heat for five minutes. At the end season with salt and pepper.
Cut half of the ham into fine strips. Prepare the mushrooms and cut them into slices. Heat the remaining butter and fry the mushrooms over a high heat. If the mushrooms draw juice, let it evaporate around them. Add the heavy cream, half the cheese, half the ham and half the mushrooms. Season with salt and pepper.
Preheat the oven to 180° Celsius. In a non-stick frying pan, fry one omelet per person in a little butter. Cover and keep warm. Cover each omelette with half a slice of ham, spread with sauce and roll up: this makes the “ficelles”. Place in a greased