Dredge shredded chicken in ⅓ cup flour. Set flour aside for Marsala sauce.
Heat 2 tbsp oil and 1 tbsp butter in a skillet over medium-high heat. Brown chicken in batches, turning, until golden. Set browned chicken aside.
Add 2 tbsp oil and 1 tbsp butter to skillet. Add mushrooms and yellow onions. Cook until onions are translucent. Set aside.
Heat remaining oil and butter in skillet and cook green onions and garlic until soft. Add remaining flour and cook for about 2 minutes. Add Marsala wine and chicken stock. Cook for another 2 minutes, scraping the bottom of skillet until sauce has slightly reduced.
Return chicken and mushrooms to skillet, and cook until thoroughly heated. Season with salt, pepper, and herbs. Serve with pasta or rice.
Recipe by Sophistishe at http://sophistishe.com/2013/10/rotisserie-chicken-marsala/