I found a wee Mexican grocery / lunch counter a bit east of Jean-Talon Market where they make good, soft but fully-cooked corn tortillas: two guys were making them: a middle-aged man was kneading some masa and a young guy manning an odd machine cooking them.
I found a tiny Mexican place a bit east of Jean Talon-Market that makes lovely soft corn tortillas - the guys roll out the masa by hand and make them in a funny little machine.
Restaurant et marché mexicain
1224, rue Bélanger Montréal H2S 1H8
There isn't much at the "Marché mexicain"; perhaps you'll find a couple of items that you don't find at the much larger nearby shop formerly known as Andes and now called Sabor latino, and the restaurant is a very glorified wee hole-in-the-wall, but the tortillas are good, and were still hot when I got home on my bicycle.