Turbot with Black Butter

Remove the skin and bones from some cold cooked turbot and cut the fish into
nice sized pieces. Put a large piece of butter into a stewpan and boil it until it
comes to be of a dark color ; then put in a moderate quantity of finely-chopped
parsley and one wineglassful of tarragon vinegar. Season to taste with pepper and
salt. Put the fish into the sauce and keep it at the side of the fire until heated
through and through. Turn the fish with the butter on to a hot dish and serve. ,