There was a Marie Callender Cafe classic froz meal which I loved that this tastes very close to. This was just excellent.
In another pan I cooked about three cups of sliced mushrooms in 1/4 cup butter until they were cooked - then added two tablespoons of flour and a 1/2 cup of chicken broth and stirred until the sauce thickened. Season with salt/pepper and served it over the baked chicken. It was really good, and really didn't need the mushroom sauce - would be good alone.