It is a little incongruous to have the strong Tibetan theme but Vietnamese food, but I guess Buddhism is the link. There is another Tibetan cafe like this in HCMC too.
I have eaten there a couple of times and both times the food was fine. I think it must have improved from the first review some years ago.
The menu is wide, but standard Vietnamese in range. Rice, noodles, hot pots etc.
I liked the banh xeo, because that can commonly be too oily, but was good at Mandala.
The hot pot (lau) was also good, and like a number of good vegetarian places put medicinal herbs and roots in the hot pot for health. I forget which hot pot was ordered (there are usually 3-4 flavours).
All in all, a good choice for lunch or dinner.
Cons: Not really stand out food