Coin
To use your gold at the bar you need to turn it into a coin. Well, more than one coin, probably. But you know for sure that you can make at least one coin out of the gold you have.
Imagine yourself strenuously pushing a lever to flatten your gold and punch a coin out it. You sweat as you hurry to make enough coins so you can go to the bar before it closes.
せん
ぜに
None
You use the coin to pay a centaur (せん) at the bar. The centaur is the bartender and he makes special drinks for those who pay in gold coins. Good for you!
Imagine handing this centaur bartender your gold coins. Hear him thank you in his booming voice and make you a mysterious gold-colored drink. Look in wonder at how the centaur has managed to fit in the narrow space behind the bar counter.