In general for a foreign chef the minimal would be 25K, 35K easy and more if you work in the more upscale/famous places. Housing/transport allowance etc are also negotiable on top of it.
Now regarding a small shop/ potentially opening a restaurant…. All alarm bells start ringing.. Shanghai restaurants often don’t last long, or don’t even get to pre-opening. Many restaurant might open with a foreign chef until you have trained your assistant and than the owner suddenly decides they don’t need you anymore..I don’t want to be too negative but without a safety net the changes of ending on a dead-end street are huge. For the little details you have shared, I guess 85% chance on a “I told you so” experience.
If you want to come to shanghai, it’s safer to join a well-know and lasting company. Go through decent job hunters who know the local market. Join Hotel groups or F&B groups who have several places and have been around for more than 5 years.
Trust me, I’ve been there and I have seen seen more all around me. I thought I was employed by a world-wide chain, however all that doesn’t count in China. The owners are pretty much free to do whatever they want.
