Where should a couple of restaurant industry guys have lunch?

Two restaurant veterans and recent fathers here. We’ll be passing thru on our way to Montreal for a boys weekend. Looking for a great lunch. Quality food and a full liquor license are the only requisites. It can be a hole-in-the-wall or farm-to-table. Any cuisine, any price. What’s the one place we shouldn’t miss since we won’t be back for another 20 years?