Serendipity3 is bringing back its Quintessential Grilled Cheese Sandwich. The sandwich holds the Guinness World Record for being the most expensive sandwich in the world. The treat will be on the menu at the New York restaurant for National Grilled Cheese Day tomorrow. The $214 grilled cheese consists of French Pullman Champagne Bread made with Dom Perignon Champagne and spread with grass-fed white truffle butter. It also includes 23k edible gold flakes and Caciocavallo Podolico Cheese, which is is both rare and one of the most popular cheeses curated in Italy. Only 25,000 cows able to produce the cheese between May and June. What’s the most expensive thing you have ever eaten?