Cod a la Portugaise

I wonder where I got this recipe?  I was surprised I hadn't posted it before, as it's so simple and flavorful.

1 onion, thinly sliced
2 cloves garlic, crushed
1/4 cup chopped parsley
1 sprig fresh thyme, or 1/4 teaspoon dried
1 cup chopped tomatoes (canned OK)
1/2 cup white wine

Place the first six ingredients in a large skillet and simmer for five minutes

1 pound cod, cut in serving pieces and seasoned with salt and pepper

Place fish in skillet and bathe in sauce.  Simmer, covered, for five or ten minutes until just done.  Cod cooks very quickly this way.

1 tablespoon butter

Remove cod to serving dish and keep warm.  Boil sauce to reduce by about one third.  Stir in butter and pour sauce over fish.  Serve at once.