Fry the champignons. To do this, pour oil into a frying pan and heat it up. Put the champignons in and fry over medium heat, stirring occasionally, until the moisture evaporates, about 10-15 minutes.
Combine the champignons with the onion. Add chopped onion to the pan with the mushrooms. Stir and fry until golden brown.
Prepare the sour cream sauce. To do this, add sour cream to the frying pan with mushrooms and onions, add salt, pepper, and coriander. Stir and fry until the sour cream boils. Then cover the frying pan with a lid and simmer for 10-15 minutes over low heat.