That evening, I had dinner with some business contacts and it wasn't really appropriate to photograph the dishes. I did however go back the next morning and photograph the menu and the outside of the restaurant. We sat at the table front right. I never saw inside the restaurant.
Click on image to enlarge
Unfortunately, I can't remember the name of the place - Something Club - but This is the “Lý Club” and it is to the west of the Independence Palace and before the War Museum. 143 Nam Ky Khoi Nghia, District 3, HCMC. Tel: +84 8 3930 5588
To my amusement, my dinner hosts all went for the western menu, whereas I went for the Vietnamese. I had Mango Catfish, Beef Knuckle and the Rambutan Sweet Soup.
It was very good, but the ambience was a bit too much above itself. And anyway, I prefer the street food. I'm cheap.
Edited to add the name of the place as supplied by @KennethT