Not sure if that is the right answer- but wouldn't that be a student visa? Again, not sure, but there used to be apprenticeships as in other countries (in Germany, for example, you are trained on the job and attend school either in blocks or once/ twice a week), they were gone for a time but as far as I know came back...., if you train as a chef and don't attend Polytech, you will work in a kitchen and attend the nearest Polytech to gain credits/ pass assessments (our son did that). so it would be a mix of work and school, but since the aim is gaining an education, a student visa would come closest, I would think?!
Probably INZ would be the best place to ask?
Ups, just read your first sentence again..., I thought about calling them