Classically, and mostly still in the English-speaking world, “À la Liegeoise” has indicated that a dish has been flavoured with juniper berries.
Dishes such as “Ecrevisses à la Liégeoise”, “Rognons de veau à la liégeoise” and “Cailles à la Liégeoise”, call for Juniper Berries and sometimes also the juniper flavoured alcohol called “pèket.”
The phrase can also be used for dishes such as “Boulet à la liégeoise” (Liege meatballs) and “Lapin à la liégeoise”, which have “Sirop de Liège” in the sauce that accompanies them. The syrup is made from boiling down apple and pear juice. Sometimes recipes may just call for either pear or apple syrup.
Language Notes
Liege is a city in Belgium.