"In the style of Bordelais or Bordeaux." There are no hard and fast rules. It generally implies a sauce of shallots, wine (red or white) butter, tarragon and bone marrow and cooked with cep mushrooms. It can also mean simply cooked in wine (e.g. pêches à la bordelaise). Alternatively, it could also be a garnish of finely diced vegetables and sometimes ham or a garnish for poultry of artichokes and potatoes. Of fish and shellfish, it might mean cooked in wine with vegetables and herbs.