I love making hamburgers! This recipe is the combination of that love and my love for Krug. The Caramelized onions, rich fattiness of the beef and cheese, and the toasted brioche bun all play beautifully with the crisp champagne. The sauce, appropriately named Champagnnaise, is a nod to the classic ’secret sauce’ but with flavors tailored for the Grand Cuvée 168ème Édition.