You wrote that big wall of text, with a lot of buzzwords thrown around, and I'm still not sure I have any idea what you are looking for.
You want a chef who can develop the menus and cook for a cafe, and for catering, and coffee, and grab and go, while simultaneously serving customers, doing email/marketing, social media, responding to guest inquiries? Lol…ok.
what is the actual concept of the business? Like a retreat or day spa?
you didn't actually say much with your post.
You don't mention your pay rate…I'm afraid to ask. Some sort of sweat equity and low pay? No health insurance I assume?
Your question is what to call this job? The closet I could come is "owner" and it doesn't sound like the person is going to be an owner…so. I dunno.
I think I'd need more information but if you tried to sell me this job I wouldn't be buying. I see your concern with getting someone on board.