I'm not French Canadian, but I've eaten plenty of genuine Montreal Style Smoked Beef during my visits to Montreal. This sub shop is as genuine as it gets, and it's in the heart of North East Calgary. We only discovered this shop recently, when a French Canadian friend of ours suggested it to us.
Portions are huge. And Delicious. My hubby and I shared a Smoke Meat Sandwich ($9.95) and a small poutine. I got a can of Grape Crush to drink, and the Mr. got a can of genuine cherry soda, imported from Quebec.
The atmosphere is very authentic and by no means fancy (and I mean that in the best possible way). There are mismatched maps of Montreal on the wall and lots of French sports clippings and posters.
The service was typically Albertan; warm and friendly.
So, that's that. Go there if you love hearty food, or have an unhealthy obsession with poutine like I do.