Line a shallow baking pan with aluminum foil and place in oven. Preheat oven with pan in at 450 degrees for about 30 to 40 minutes. Brush the hot pan with melted butter and arrange the fish pieces in the pan. Sprinkle them lightly with flour and place a dab of butter on each piece of fish. Bake and time the baking based on the fish thickness, -10 minutes of total baking time per inch of fish thickness. If the fish is 1/2 inch thick, the total baking time is 5 minutes. If the fish is 1/4 inch thick, the total baking time is 2 and 1/2 minutes. Garnish each piece with a thin slice of lemon on top, sprinkled with parsley or paprika. Serve with lemon wedges and your choice of a side dish.