Preheat oven to 350F.
In saucepan, combine wine, juice from crabmeat, 1/4 cup green onions, 1 teaspoon oregano, garlic, bay leaf and salt and pepper to taste. Bring to boil and simmer 5 minutes. Place fish in glass baking dish and pour hot herbed wine over fish. Bake for 10 to 15 minutes until fish is flaky.
While cooking, prepare sauce by melting butter in a saucepan and adding the rest of the ingredients except for cornstarch and milk. Cook until onions are tender. Mix cornstarch and milk together. Add to saucepan and cook until thickened, then serve over wine-poached fish.