There is a loophole.
If you are cooking for a company, that is not open to the public, and you are not serving anyone but the employees, you are allowed to cook as a private party. You do not NEED any insurance or tax information. However, can you and should you are different issues.
ServSafe is always advisable, however, again, you do not NEED it to do this job. It will protect you should something go wrong. Single event insurance will run around $150 for the event.
me: I don't drink anymore
Yelonutz: me either, but, then again, I don't drink any less