In a small bowl, mix parsley, oregano, lemon zest and garlic. Set aside. Add salt and pepper to the chicken breasts.
In a large skillet, melt butter at medium-high heat. Add chicken breasts and cook for 6 minutes or until browned (flip at mid-cooking). Remove chicken breasts from the skillet and set aside on a plate. Add half of the parsley mixture and chicken stock. Bring to boil, stirring and scraping the bottom of skillet to remove the browned bits. Put the chicken back to the skillet. Reduce heat, cover and let simmer for 8 minutes or until chicken is not pink inside.
When ready to serve, drizzle sauce on each serving and sprinkle with remaining parsley mixture.