# Clean the liver
and dice it, put into a pot. Add 8 cups of water on it and boil until it softens.
# Remove the bubbles over the water during the boiling and let it cool down.
# Put the butter and vegetable oil into a separate pot. When the butter melts, add flour
in it and roast it, until the flour
turns to yellow.
# Add the water of the liver
into the mixture at once. When it starts to boil, add the liver
# Meanwhile, prepare the liaison; whisk the mixture of lemon
juice and egg well. Get 1/2 cup of cooking soup and pour into this mixture and whisk it well again.
# Pour the liaison into the soup slowly, stir and add salt in it.
# When the soup reaches to the boiling temperature, remove it from the stove and serve hot.