Why is Shepard's pie called pate chinois in french?

One possible explanation is that it was introduced to Canadian railway workers by Chinese cooks during the building of the North American railroads in the late 19th century.

It is French Canadian invention

Pâté Chinois is not a Chinese recipe. It may simply be an adaption of "Shepherd's Pie", but one possible explanation for the Chinese reference is that it was introduced to Canadian railway workers by Chinese cooks during the building of the North American railroads in the late 19th century.[citation needed] These cooks made it under instruction from the railway bosses (of English extraction) as an easily-prepared, inexpensive version of the popular cottage pie, with the sauce in the tinned creamed-corn serving as a substitute for the gravy.

Dune

Chinese Pie