I can't say enough wonderful things about this bakery. It's probably one of the best I've been to for croissants...in the world. Small and unassuming from the outside, the activity inside is an endless flurry of pastry-packed baking sheets being pulled out and put into the ovens. The prices are very reasonable but beware that it's cash only. The croissant and kouign amman were placed into a paper bag - seconds later when I opened the bag on the street, a rush of steam poured out, surprising me that both were incredibly warm.
As others have said, THE BUTTER. These are the butteriest pastries I've had in a long time, and I thought it was gorgeous that each crispy-then-soft-and-steamy bite of the croissant tasted like each layer had been carefully rolled and infused with shredded lard. Gross? No. Life-changing. The kouign amman was amazing itself - buttery, sugary, perfectly carmelized and crunchy.
I will never again return to Montreal without coming here!