How to sell homemade sauerkraut and herbs in the city?

I live in Brooklyn, NYC and would like to sell my homemade sauerkraut and herbal tinctures and oils.

What is the best way to do this? I probably couldn't support getting an entire farmers market stand. Would some stands buy my products and sell them?

I would also like to grow mushrooms indoors and sell them. Maybe to some local restaurants and grocery stores?

How can I sell to these places legally? Do I need some kind of certification or registration with the city?

Every state has its own regulations regarding the sale of processed foods.
(Raw cabbage is easy.  Sauerkraut requires inspections.)
Almost all states require that this processing be done in a certified kitchen.
Many cities and counties have their own regulations.

A certified kitchen must be open during working hours (for the food safety inspectors).
This basically means that if you work a day job, and make your sauerkraut in the evenings, you are not open for inspections.  They tend to be more favorable to full time operations than they are to moon lighting home industries.  Some states do have cottage industries provisions, but most do not.  They want to hold a business accountable, not an individual.