My wife, a Thai national, no visa needed, did one of those cooking courses. A graduate from the Ramkhanhaeng University, Bangkok. She has always been a good cook (could make 320 different Thai meals) and she got a certificate from the cooking course.
With that, she got a job in a Thai restaurant in Japan (Nagoya) and worked part time (only lunch time when white collars come for lunch, 3 hours a day).
Still, she was cutting, preparing, serving 120 meal sets within 3 hours. But had never had access to the pan and fire. That was for a Thai chef, who went through a Hospitality high school, where cooking was last 2 years of the 4 years of that vocational school.