The Zen Master

A zen master is visiting New York City from Tibet. He goes up to a hot dog vendor and says "Make me one with everything."
 The hot dog vendor fixes a hot dog and hands it to the zen master, who pays with a $20 bill. The vendor puts the money in the cash box and closes it.
"Where's my change?" the zen master asked.
The hot dog vendor responded "Change must come from within."

What do you think happened next?