Let me preface this by saying that I am not a fan of vegetarian restaurants, probably because of too many wretched meals at The Source back in the Seventies. Woody Allen was right about that place.
That said, tipped by my mother-in-law's manicurist(yes, you read that correctly) part of my family trekked down en masse to a Vietnamese vegetarian restaurant called AU LAC on the edge of Litte Saigon in Westminister last weekend and it was, in a word, sensational. To begin with, all those irritating little phonies like "vegetarian beef", "vegetarian chicken" and "vegetarian shrimp" actually tasted like the real thing. But better than that, they were superbly prepared, particularly the beef which came with a peppery watercress and was so good it tasted terrific several days later out of the leftover box. That old standby sweet-and-sour chicken was far better than in its usual form, less greasy. In fact none of the food from the extensive menu was oily at all. It tasted healthy and GOOD, believe it or not? Spring rolls and other conventional Vietnamese fare were fine, the menu extensive and original.
The owner (Mei) is a Vietnamese woman married to a doctor who is quite personable and intelligent and will explain her unique cuisine which appears to have been discovered by some of the Orange County academic crowd who occupied a couple of tables when we were there. It's not expensive and adjacent to the 405 with good parking (not an easy thing in the center of Little Saigon on the weekends). I'll try to dig out the address but I'm sure it's in the book under Santa Ana or Westminister. But stay away this weekend. It's Tet.