Update: After a gap of nearly four years, I can say that Happy Veggie is not as good as I remember it. The service was spacey and weird, with multiple servers, though the young woman who helped us was friendly and attentive. I found my curry vegetable lunch special ($9) to be passable, but under-seasoned. The pumpkin soup that comes with the lunch special was pretty good, however. Brown rice costs $1 more which made this meal not much of a value (it's good for a single meal, but I'd like to have leftovers for $10 worth of food from a stripmall joint).
Lastly, we got the tiramisu ($4.50) and coconut cake ($4.50) for dessert. The tiramisu was tasty, but came to us semi-frozen, which made it difficult to eat. I wish they'd thawed it. The coconut cake was dry and did not taste of coconut or anything, really. We complained and they at least took it off the bill.
All in all, Happy Veggie is now run of the mill and not unlike the dozens of other vegan Thai/Asian restaurants in the LA metro.
Original review (October 12, 2008): I loved this place. It's a cute little place with a super-friendly hostess (who was on the phone organizing an animal rights meeting when we entered). The decor is bright and inviting.
The food was spectacular. My mock chicken in curry sauce took me back to Thailand---the coconut curry was amazingly rich and filling, along with potatoes and excellent mock chicken. My friend's Mongolian mock chicken was also savory and subtly sweet, with a great array of vegetables.
Our vegan cheesecake was fresh and light. My only gripe was that our hot tea was served with our food, though we wanted it earlier. Other than that, I was greatly impressed with Happy Veggie and will definitely return whenever I'm next in LA.