First cut each breast in half lengthwise. Flatten each chicken breast half with the flat side of a meat mallet. Then coat each chicken piece with flour. In a skillet melt one tablespoon of butter and add four of the chicken pieces. Cook for two minutes on each side then transfer to a 3 quart rectangular baking dish. Then repeat with the 4 remaining pieces and one tablespoon of butter. Now add the last tablespoon of butter to the empty skillet and add one 8 oz. can of sliced mushrooms that you have drained. Cook for a few minutes and then stir in 1 cup of chicken broth, 1/2 tsp. of salt, and 1/4 tsp. of pepper. Then bring to a boil slowly so the sauce will reduce down. Then add 1 tablespoon of flour to the sauce to slightly thicken it. Pour the sauce over the chicken in the baking dish. Then top with 1/2 cup of shredded mozzarella cheese and 1/3 cup of grated Parmesan cheese. Bake uncovered in a 375 degree oven for 20 minutes or until the chicken temps at 165 degrees on a meat thermometer.