On the face of it, putting together the perfect burger seems pretty straightforward. After all, as long the bun's good and what's inside is even better, things are going to work out…right? While that's true to an extent, burgers are much more layered than they're given credit for. In Shanghai, these pillars of comfort can be stuffed with anything from foie gras to truffle and wagyu patties doused with blue cheese. The options are endless, so to make it easy for you, here are some of our favourites.