It is a speciality of the French region of Alsace, and may be served hot, warm or at room temperature.

Onion pastries are familiar in many French regions and elsewhere, including the Provençal pissaladière, Flemish flamiche and from Britain the Lancashire Butter pie.

[1] Elizabeth David singles out Zewelwaï as "the famous Alsatian speciality ... a truly lovely first course".

Different cooks and writers specify various fats, including butter and oil (David),[2] lard (Jane Grigson),[1] beef dripping (Felicity Cloake), olive oil (Gilles Pudlowski),[1] butter (André Soltner),[3] and goose fat (Anne Willan).

[1] A variant made in the early months of the year, Zewelwaï printanière, substitutes spring onions for the usual brown ones.