Wikipedia has an excellent entry into Food guides in Hong Kong, the link is as follows:

http://en.wikipedia.org/wiki/Cuisine_of_Hong_Kong

It covers the main areas, it is not a restaurant guide, but more specifically a guide to the kind of foods and food styles available in Hong Kong.

Hong Kong’s only Austrian restaurant, Mozart Stubn is open again, serving the best Schnitzel and Goulash in town. The website appears a little outdated but a recent advertising indicates that they are back in full force, if you want to try something different, it’s well worth it.

http://www.hongkongfoodguide.com/ is, as the name indicates, a guide to food in Hong Kong. It’s not very comprehensive, only covering the main districts and is more factual, without actual real commentaries, so if you are looking for simply a directory of food, this one isn’t bad.