Jiro Ono is a Shokunin.
Shokunin is often translated as "Artisan" or "Craftsman". Which while not incorrect, is certainly incomplete.
A shokunin may at first glance seem like a workaholic. And perhaps some workaholics are actually shokunin, but not being Japanese, do not have the privilege to be named as one. (Interestingly, the Japanese also have a term "Karoshi" which means "death from overwork".)
But a shokunin is more than just a workaholic. It is not simply work, it is art, it is a calling, it is the pursuit of perfection, it is the continuous journey to understanding, achievement, and fulfilment of the full potential and purpose of the work.
One Japanese suggested that the shokunin pursues his craft for the benefit of society. His view may be culturally biased. Another (non-Japanese) disagreed and suggested that the shokunin is centred on his achievement, his skills, his development, and his attainment of perfection. This is a rather idio-centric view and explanation of a shokunin's mindset.
My view is that a shokunin is not simply a workaholic. A workaholic (like an alcoholic or any other kind of addict) is either compensating for some defect or lack in his/her life, escaping from life, or both. A shokunin is attempting to achieve perfection. Not for others. Not for himself. But perfection is its own goal.
"Jiro Dreams of Sushi" is about one man's pursuit of perfection in sushi. It is both a very narrow focus, and an impossible subject for a movie, but succeeds anyway.