Last week I got some take away Yum Cha at a restaurant in Castle Hill called
Hilltop Phoenix. The food was really good, but their service was
DREADFUL. The staff treated me with contempt.

So if you like good Chinese food but don't mind being treated like sub-human crap, then go for it.
Some restaurants that I would recommend are:
Ichi-Ban Boshi - located in Sydney's Bondi Junction
(or "Bonjan" in Japanese
) and Victoria Galeries building (opposite Kinokuniya) and Gold Coast's Southport. The food and service are great, only downside is that you have to queue as they don't take bookings. Recommended if you're not in a huge hurry to eat right away.
Zenya Noodle Bar - I was surprised to find an _authentic_ Japanese restaurant in Sydney's Eastwood (home of Hasbro Australia)! But yes, the cuisine is authentic and the service is okay.
That'll do for now.
