Chop onions and mushrooms. Fry for 10 minutes in vegetable oil. Salt and pepper.
Grind mushrooms and onions with a blender. Then add a glass of broth and whisk again with a blender.
Melt the butter in a saucepan, add flour and fry for several minutes.
Transfer the mushrooms into the pan, pour in the rest of the broth and cook after boiling for 5 minutes.
Pour the cream into the soup, bring to a boil and remove from heat. Serve with crackers.