In 1904, the St Louis World’s Fair called the hamburger “the innovation of a food vendor on the pike.” This meaty sandwich has been served at bars, fine restaurants, steak houses, and kitchens across the world ever since. The greatest sandwich I ever ate was at a hole-in-the-wall in Montreal, Canada. On a cold December Saturday, I trudged through three feet of snow. Looking for a place to warm my toes, I instead found a treasure trove of taste. I’ve tried for years to duplicate it, and here’s the closest I’ve ever gotten.