I don’t know what such a thing might become but I can come up with a few rough ideas off the top of my head.
Healthy food, locally produced and fairly traded. Reasonably-priced food. Cruelty-free food. Educating people about food issues. Addressing the ludicrous amounts of food wasted by supermarkets. Encouraging people/communities to grow their own food. Community events, using food as a way to bring communities together. Catering at outside events, both for fundraising and spreading the word about campaigns.
Many of these are of necessity more commercial than the kind of things the RHN is typically involved in. That probably means it will need to start small and expand its ambitions as its capacity grows. For example, local bulk buying groups are comparatively easy to set up and there could be many benefits from bringing these groups together in a loose network.
(Feel free to add your own ideas, expand on these, etc…)