A Cardassian condiment that Quark was left holding in bulk after the occupation ended, and the starting point of Jake and Nog's first trading venture in Progress.
Yamok sauce is used to flavour Cardassian food. When the Cardassians abandon the station, demand for it disappears overnight.
In the Deep Space Nine episode Progress, Nog overhears his uncle Quark raging about five thousand wrappages of the sauce that nobody will buy. He and Jake Sisko take it off his hands and look for a customer, finding a freighter captain who supplies Cardassians and is willing to trade a hundred gross of self-sealing stem bolts for it.
Neither boy knows what a stem bolt is, but the deal starts a chain of swaps that turns unwanted sauce into a parcel of Bajoran land and then into latinum, when Quark discovers the government needs the plot. The boys call themselves the Noh-Jay Consortium.