Place a cover over the dish and drain out all the cooking liquid into an enameled saucepan. (*) The fish is now poached and ready for saucing. It may be covered and kept warm for a few minutes over hot, but not simmering, water. Or set it aside, covered with its piece of paper, and reheat later for a few minutes over simmering water. Be very sure the fish does not overcook as it reheats. Before saucing the fish, drain off any liquid which may have accumulated in the dish.