Divide chicken into pieces, season with salt and pepper and fry all around in butter until golden brown. Remove from the pan and keep warm.
In the remaining fat, fry the onion, cut the mushrooms into slices and fry them as well. Deglaze with white wine.
Add the chicken pieces, cover and steam until done.
Bind the juice with starch flour and butter and bring to the table, sprinkled with parsley.