In a shallow dish or bowl, mix flour, salt, pepper and oregano. Roll pieces of chicken in flour mixture.
Melt the butter in a large skillet over medium heat. Place the chicken in a pan and sauté until brown.
Fry the mushrooms. Pour with wine and sherry, cook for 5 minutes. then add the broth and spices, put the pieces of chicken and cook for another 10 minutes. periodically pouring them with sauce.
Serve hot chicken with mushrooms and sauce.