For more than a decade, grilled cheese fans have flocked to Kappacasein at London’s Borough Market. Cheese expert Bill Oglethorpe’s melty masterpiece consists of grated Montgomery Cheddar, Comté and Ogleshield cheese mixed with red and white diced onion, garlic and leeks. Cradled between slices of Poilane sourdough bread, the sandwich is toasted until it reaches golden perfection with cheese oozing out of its pores. Legendary American food writer Ruth Reichl described the sandwich as the "Platonic ideal" and the highlight of her trip to England. Don’t miss it.