Steak, blé d'inde, patates...

The Chinois seems to refer to the Chinese people that were employed to build the national railroad in the last century [19th, that is]. The usual meal was a mix of food that was cheap & abundant: corn, potatoes, beef.

That's what you can read in the Guide du Routard of Québec, kind of Frommers guide in french. I called a friend who studied ethnology, and she gave me the same answer. However, in both case, there was no sources, so I can't verify elsewhere. I can't explain either why the pâté chinois only survived in Québec, while the railroad crossed the whole Canada. It seems like the explanation, like the dish, belongs to the folklore...