Tai Ping Koon Opens as Hong Kong's Soy-Sauce Western House
ESTIMATED75% CONFIDENCEWikipedia[1] states that the founder "established it in 1860 as a restaurant serving Western cuisine" and gives no month or day, so the pin takes that year's last day.
Tai Ping Koon was established in 1860 serving Western food to Chinese diners, and in doing so more or less invented the genre Hong Kong calls soy-sauce Western - Swiss chicken wings in a sweet soy braise, baked pork chop rice, souffle to finish. It began in Canton and became a Hong Kong business alone when the Canton branch was confiscated and closed in 1956.