In a shallow Pirex or Corningware baking dish I bake split chicken breasts @ 325 for about an hour. During the last 15 minutes, you can kick it up to 425, which will "brown" the skin on top.
In a separate pan, and with about 15 minutes to go, I sautee a pound of the white, Pennsylvania-type mushrooms (whole) in butter. Any mushrooms will do... it's your kitchen, do what you want. Cut any mushrooms as large as a silver dollar in half, otherwise, if they're a half-dollar size or smaller, leave them whole... the mushroom flavor and moisture stays in better. I trim the stems a bit. Add a little garlic salt, some onion powder, salt and pepper to the sauteeing mushrooms. When they start to soften, I add half a can of chicken stock and continue to simmer on medium heat.
Now, when you pull the chicken out of the oven, remove the breasts from the baking dish. Put the dish on a burner and use it to make a thin gravy with your flour and water, or what I do, I use the remainder of the chicken stock. When the gravy boils it will start to thicken... now add the mushroom mixture into this. If the chicken has cooled you can place in back in the corningware dish to warm it up
Now "plate" the chicken breasts, smothering them with the whole sauteed mushrooms in gravy. I serve Stove-Top Stuffing with the chicken and you've got my permission to hit that with a little gravy also. Mashed potatoes also works great as a side dish as does white rice.
Want to kick it up a notch? Before sauteeing the mushrooms, place the (optional) onion and garlic in the pan. Allow this to "soften" before adding the mushrooms.
Enjoy... you're "good to go."
Airborne