If you had asked the question 23 year ago when I moved to China, the list would be very long. However, I can now get most things. online if not in the local markets or shops.
The only thing that springs to mind now is fresh herbs other than coriander leaf/cilantro and mint. I managed to find some basil seeds and had a healthy crop when I left for three weeks in the UK. Hope they survive.
I'd grow more but it's illegal to import the seeds.