Take a slice of bread. It's perfectly okay in and of itself. Maybe it has a nice, crisp crust or the scent of sourdough. But really, it's kind of boring. Now melt some cheese on it--a sharp Vermont cheddar or a flavorful Swiss Gruyere. Mmm, delicious. Cheese--it's the staple food, the accessory that makes everything better, from the hamburger to the ordinary sandwich to a bowl of macaroni. Despite its many uses and variations, there has...