Sometimes in English, they are called steamed buns.
Here's a picture:
The Hong Kong question might become outdated soon, although the popular figure is that 96% of people that live in Hong Kong speak Cantonese, I don't think that is remotely the case anymore. The language is sadly fading away, especially with the younger generation where it is not being taught anymore. By the time of the next census, I can safely say that there will be more Mandarin speakers in Hong Kong than Cantonese ones.
Source: Speaks Cantonese and lived in Hong Kong