The beef broth at stall 2 goes on at nine in the evening and is strained at nine the next morning (sample).
Twelve hours on a low heat is what makes it clear and deep at the same time. The noodles, by contrast, take ninety seconds: pulled by hand when you order, dropped in, lifted out.
The vegan broth came later, at the request of the Green Bowl regulars next door. It is made with dried mushrooms and kombu and simmers for three hours.