In Europe when you travel the Autobahn, legend goes that the best food is found where you see the most trucks. Well, it is a legend. Not always, but sometimes true.
In China, I can safely say that the best food I had was on the side of a road or at markets, where fresh ingredients made for some lively, tasty meals. Fresh fish in the south, spicy foods in Shanghai, noodles in Beijing, always the best in small places on the road sides. GF is not a challenge, noodles are mostly made of rice, all else is fresh and not pre packaged (yet). Not to mention that you can eat for under $3.00, bottled water included.