Any time you are feeding the public, regardless of the situation or location, you are subject to regulation. Of course, this would exempt family and friends within a home situation. Otherwise, particularly if you are taking money or services in trade, you are subject to all of the requirements for safety. If you want to run under the table, that is your business, although, you do that and folks get sick, or you provide bad food, you sully everyone else, even those who go by the books.
You will find little support amongst most of the professional Brethren for what you seem to want to do, as they are doing it legally and paying the costs associated with that. I think I can speak for all of the folks currently working professionally, nobody appreciates the illegal taco trucks, sandwich carts and hot dog stands who are taking business by not playing by the rules.