The traveler didn't seem to mind. He made camp and started a fire, then filled the pot with water from a nearby stream. While the villagers watched he dug deep into his pocket, fished out a smooth stone, and dropped it into the boiling water.
Curious, the villagers asked: "What's that? What are you making?"
The traveler smiled. "Ah, it's my Soup Stone! They're quite rare and difficult to make! This one is particularly fine; perhaps you'd like a taste, when it's ready."