By cooking pot, do you mean something used to cook with?
If you use it to grow plants, the number one issue will be drainage. Ideally containers need to have drainage from which water can flow out of the container. Otherwise excess water may sit at the bottom of the container and cause the roots to rot.
Another thing is with such container, depth is often more important than the diameter of the container itself. You mention 4cm as one of the dimension, which one is it? This seems really small.
And to answer your question, yes I would go with herbs instead of vegetables. You could go with one herb like thyme (good for shallow containers), mint, rosemary or something similar.