I found another "clean and expensive" one, mainly Mandarin-HK style but also featuring some Vietnamese delicacies such as Bao and Summer Rolls ...

Cafe Chin Chin located in the Tustin Marketplace, Tustin, CA

Food is pricy but all is made fresh to order and the taste is fabulous. One of their specialties, Orange Chicken has a much more delicate taste than most places I've tried which go over the top with sweetness. Definitely worth trying.