I guess HK has people from pretty much everywhere (I recall a sizeable Indian population, no? I certainly remember eating several excellent Indian meals.).
I'm glad you mentioned the Asian ex-pats. So often, I have heard people (other foreigners) here saying that there are only about 12 foreigners in the city, when they mean 12 white westerners. (The black westerners in town are all African according to the locals. So far as I know, none of them are. One is from Manchester, England and the other from California.)
We have a large number of Vietnamese and Thai students studying Chinese and various other Asian people working in the city. A few years ago, I befriended a lovely Japanese woman who was here teaching her language. She would, from time to time, invite me and some others for Japanese home cooking which was always interesting and delicious. (Not Asian, but there was also, about 18 years ago, a Mexican family who invited me to eat their home made food, too. I know almost nothing about Mexican cuisine, so that was always a treat.)
One idiot who is thankfully long gone used to continually complain about the "illegal immigrants" plaguing his country. I found later that he was here working on a tourist visa. Strictly illegal.
The ex-pat community is in constant flux as people are mainly here on short-term contracts or leave after their study courses are completed. I only know of three semi-permanent residents: Myself (I've been here longest), an American friend who lives nearby but I only see about once every two years for a beer or some meatloaf cooked by his Chinese wife! The third is a young man from the Czech Republic who teaches English in a kindergarten despite not really being able to speak English! The kids only need "Hello! How are you?" We nod to each other on the few occasions we meet.
Despite being so close to Vietnam, there are no Vietnamese restaurants in town apart from a couple of not very good noodle places. There are two Thai places. Both Chinese operated. One is very good; the other just cooks Chinese food and sticks a quarter of a lime on top, instantly rendering it Thai. The steak and pizza places which are so fashionable at the moment are all dire. The chefs have never seen an actual pizza in their lives and they have little idea how to source or cook good steaks. I stick resolutely to Chinese food. The locals have worked out how to cook that to perfection.
So, a visit to HK is when I recharge my "other foods" batteries. Irish, Indian, Italian etc..