Rub some Italian seasoning or curry powder or something on those chicken breasts before cooking to help get rid of the plain-ness. Add some cans of drained mushroom pieces, and a bunch of fresh parsley to the soup.
This amount is right at the edge of the amount you can do in one roaster.
How I would do it is, spray the cookwell/pan with nonstick spray, put all the soup in and preheat to 325, this will take at least 25 minutes. Then slide in the chicken breasts, which have been out of the refrigerator for just 20 minutes. Cover, stir occasionally, cook until the internal temp of a breast in the middle is 165- USE A QUICK READ THERMOMETER TO CHECK THIS. This can take anywhere from an hour to 2, depending on the size of the breast pieces.
As soon as it reaches this temp, turn to 180. Will hold up to 2 hours.