Preheat oven to 400 degrees. Greased 13x9 inch baking pan.Place the chicken breasts between 2 sheets of wax paper, pound down to 1/4 inch thickness.  Dredge the chicken breasts lightly in flour.Place 2 Tablespoons of butter in a large saute pan heated over medium heat. Add 4 chickens breasts to the pan. Cook the chicken breasts for 2 to 4 minutes per side until golden brown or until no longer pink in the middle.Place those 4 chicken breast in a greased 13x9 inch baking pan overlapping edges. Add the last 4 chicken breast to the saute pan along with 2 more Tablespoons of butter, cook the same way you cooked the first four chicken breast, also placing them in the baking pan when done. Reserving the drippings in the pan. Add the mushrooms to the drippings in the pan you sauteed the chicken in. Add a 1/4 cup butter to the pan, saute mushrooms 3 to 4 minutes of until lightly browned. Sprinkle the mushrooms over the chicken breast in the baking pan. Add the wine (or chicken broth if using it to substitute the wine), salt, garlic powder and the chicken broth to the drippings in the pan. Simmer 10 minutes, stirring occasionally. Spoon the sauce over the chicken in the baking pan evenly. Place the pan in the preheated 400 degree oven for 10 minutes. Remove the pan from the oven. Combine the grated cheeses together and sprinkle over the chicken. Bake an additional 5 minutes or until cheese has melted.