Halibut Florentine without milk

1 lb firm white fish fillet (preferably Halibut) 3 tablespoons butter 2 tablespoons flour 1 cup milk salt & pepper 1/2 cup parmesan cheese (divided) 10 ounces[...]

2 cups shredded cheddar cheese 1/3 cup grated parmesan cheese 2 cups half-and-half cream 1/4 cup flour 1/4 cup water 2 (10 ounce) packages frozen chopped[...]