We wanted to know more about li hing mui powder as soon as we tested the Side Street Inn's Side Mui cocktail. We learned that this oomph-imparting, sweet-salty-sour substance is ground from a type of whole dried plum flavored with salt, licorice, and saccharine. These dried plums originated in China, where they were traditionally eaten by soldiers traveling long distances. In the 1800s, they were introduced to Hawaii, where they're known as crack seed, and are a snack found in numerous variations. Whole, they're sucked on like gum balls; the powder is sprinkled atop anything from sliced fresh fruit (li hing mui mango, anyone?) to popcorn, cake, even a glass of cold beer. To that, we say, "Pucker up!"