We are not talking about cooking here. We are talking about how people cheer up each other in Hong Kong.
In Chinese, when people want to cheer up others, we would say “加油” which literally means “add oil”, similar to the meaning of “power up” or "keep going" in English. In Cantonese dialect which Hong Kong people mostly speak, it is pronounced as “Ga Yau!”.
Since the late 90s when people started using instant messenger to chat, many Hong Kongers would chat in English, sometimes in ”Chinglish” by combining Chinese and English. People started typing “Add Oil” when they want to cheer people up and the phrase has become so common now that even Oxford Dictionary recently added the explanation of this phrase.
This phrase can be viewed by their paid members.
Now you have learned this term and you can start interact with Hong Kongers by saying “Hong Kong Ga Yau”!