Do it through a border run agency. They check your previous entries in your passport and as long as they accept your application, you can be sure that you will get an entry stamp.
Read his answer to me: He is already so qualified, that he thinks he knows it all. Beiing a student in a school isn't the right place for a culinary mastermind like him. 😉
As a Visa student, you don't teach classes; you participate in them. You're looking for a suitable option for a 6-8 month stay, and learning Thai cooking would certainly be a good option. Any chef can do this, a Cordon blue Chef or even a Michelin-starred chef.
Or are you that kind of chef who already knows everything and can't learn anything new?