Here is a link to the Sonoma County PRMD website which details zoning regulations.
This property appears to be zoned Rural Residential (RR). It is also under 2 acres. The best thing for you to do is to review these regulations(they vary for lot sizes under vs. over 2 acres) and then visit or call the planning department to discuss your concerns with a planner. It is difficult to tell from the information you provided what the scope of your kitchen activities would be.
Hope this helps you to get started! There is a link to a short post I did on PRMD below.