Hot chocolate was an exotic warm chocolate milk drink. It had many aficionados, some of the most famous being Lando Calrissian and Luke Skywalker. Skywalker had grown so fond of the drink that he had kept a secret stash of the pods used to make it aboard his brother-in-law's freighter. His wife Mara Jade also enjoyed it. Hot chocolate was frowned upon in Palpatine's court, as Imperial officials preferred strong alcoholic beverages. After the Yuuzhan Vong War, hot chocolate became a rarity, because the Yuuzhan Vong had re-shaped seven of the eight planets that were home to the plant that produced the pods that were used to make it during the conflict.
Helpful instructions on how to prepare this "hot chocolate" can, thankfully, be found here.