À l’Ailleule is a French expression meaning prepared in the manner of your ancestors (more literally, of your great-grandmother.)
In terms of meaning “old-fashioned cooking”, it is perhaps somewhere between à l’ancienne and à la bonne femme.
À l’ancienne is far more commonly heard and seen these days than à l’ailleule.
Language Notes
Ailleul is great-grandfather (ajòu in Gascon); ailleule is great-grandmother (ajòla in Gascon.)
Pronounced “ayooul”.