In a shallow dish, combine flour, salt, pepper, and oregano; mix until well incorporated.

Coat chicken pieces in the prepared flour mixture.

In a large skillet, melt butter and heat olive oil over medium heat.

Place chicken in the skillet and cook for 2 minutes until lightly browned.

Flip chicken pieces and add sliced mushrooms to the skillet.

Pour in Marsala wine and cover the skillet.

Cook for 10 minutes, turning chicken once, until no longer pink and juices run clear.

Remove from heat and serve hot, garnished with herbs if desired.