Season the chicken with salt, pepper and the garlic powder. Dredge it in the flour.
Heat the oil in an ovenproof skillet. Add the chicken and cook until golden brown on both sides, about 5 to 6 minutes per side. Remove the chicken from the skillet to a plate.
Melt the butter in the skillet. Add the mushrooms and cook until soft, about 5 minutes. Add the marsala and chicken broth. Cook about 2 minutes.
Put the chicken back into the skillet and cook about 3 to 4 minutes. Top the chicken with the cheese and minced parsley.
Bake in a preheated 400-degree F oven for about 5 to 6 minutes or until cheese is melted.