I rarely give 5 stars but I seriously love Boustan. In fact, it should be a religion. Their food is just heavenly and I drool just thinking about their potatoes. Their delivery takes a while but they do tell you how long (usually 45 mins - 1h) over the phone and I'm convinced they give you more food when you order at the store.
Honestly a rite of passage if you ever live/visit/stay in Montreal. Even Pierre Elliot Trudeau (former Canadian PM) was a huge fan.