Cover the fish with the sliced mushrooms. Sprinkle with the green onion. Sprinkle with the lemon juice. Add wine and sprinkle with salt and pepper. Dot with butter
Bake at 300 F or until the fish flakes to the touch of the fork. Pour liquid off from baking dish. Boil in a saucepan on top of the stove until the liquid is reduced to one half its volume. Pour over fish and serve.