Nothing says umami like chicken, marsala, and mushrooms.
Mix the flour, salt, pepper and oregano together in a shallow dish, and coat the chicken pieces in there.
Melt butter in oil in a big skillet over medium heat. Cook the chicken pieces in the pan until lightly brown, then turn it over and add the mushrooms. Pour in the Marsala wine and sherry. Put a cover on the skillet and let the chicken simmer for 10 minutes, turning once, until they lose their pink and the juices run clear.