Often known as a Taiwanese hamburger, the gua bao is the country's quintessential snack. Braised pork belly, pickled greens, crushed peanuts, and cilantro encased in a steamed, shell-shaped, soft bread bun is a winning combination of flavors and textures. This is the go-to snack for many in Taiwan from early morning to late at night, but where did the gua bao come from?