So Ng Ka Py is the Cantonese name for a Chinese spirit or liqueur that might be an infusion of five kinds of fruit peel. A sort of alcoholic Five-Spice Powder, perhaps?
Actually, it's an infusion of a herb named Wu Jya Pi or Bark of Five Additions in the Mandarin dialect (Japanese gokahi, Korean ogapi), also known as Cortex Acanthopanacus.
Traditional Chinese Medicine uses this herb - mostly from Sichuan Province — as a tonic to treat problems of the liver, kidney, joints and some other conditions.
Alcoholic content of the spirit is high - about 48 percent or 96 proof. And the taste is intense and not to everybody’s liking - this led to its inclusion in an unusual mixed drink, as we shall see. Ng Ka Py often comes in a squat ceramic jug.
The distinctive flavor and aroma of Ng Ka Py led to its appearance in John Steinbeck's East of Eden, in which Steinbeck tries to describe the flavor: