In a shallow dish, mix together the flour, salt, oregano, and pepper. Coat chicken pieces in flour mixture. In a large skillet, heat butter and wild mushroom and sage olive oils over medium heat. Place the chicken in the pan and lightly brown. Turn chicken and brown on other side. Add mushrooms to pan and saute. Pour in marsala wine and sherry wine vinegar. Cover skillet and simmer chicken for 10 minutes, turning once, until on longer pink and juices run clear.