Gars if you want a more modern take on Chinese food in a nice setting and easy access in central Brighton amongst all the shops and pubs.
China China for a more authentic but much more basic setting and a little further out from the centre but on Preston Street which is packed with restaurants whose menus you can check out.
Other excellent places to eat Asian/Indian cuisine include Moshimo for japanese so could get gyoza instead of dim sum.
Chilli pickle is my absolute favourite for Indian and they do momos which are Nepalese steamed dumplings (I think)
Indian summer and curry leaf cafe are close second.
To be honest I could write an essay on good places to eat as I’m a foodie and making it my mission to work my way through Brighton’s best places to eat.
64 degrees is just a stunning if you want to spend a bit more and experience modern dining in an informal setting. Gets very booked up though.