Wash the fillet, cut into small pieces. Peel the onion and cut into small rings. Heat the water and add sour cream to it, stir.
Heat a frying pan with oil on the stove, add chopped onion and fry until golden.
Reduce heat slightly and add chicken to onions. Cover with a lid. Wait until all the fillets are almost white and add salt and spices.
Chop the mushrooms and add to the chicken with onions, stir and leave to simmer for 5-10 minutes.
Add sour cream, previously mixed with warm water. Mix well and simmer for another 8 minutes.
Sprinkle the fillet in sour cream sauce with fresh herbs.