It depends what you are looking for. The best kabobs IMHO are at Raffi's Place (Aremenian owned) in Glendale - where I think the beef soltani & the whitefish are excellent (they are closed on mondays). In downtown LA try Shekarchi (Iranian owned) for excellent persian kabobs (open Mon - Fri).
I think that to get a good kabob you have to leave the Westwood are. If you are in O.C. the original Darya across from South Coast plaza is good.
There is a place in Westwood for lunch time cuisine, I think it's called Atari & if I remember correctly it is across the street from the 7-11 and you enter through a courtyard.
Also in Irvine, Wholesome Choice market is a persian grocer with a Whole Foods style hot foods section.
And for the rest, I am sorry to inform you, none of the restaurants come close to the stews that we have at home! If my grandma ever opens a restaurant, I'll let you know.
I agree that there's nothing like homecooked Persian food, but I just wanted to point out, if there is a good Persian restaurant out there, it's most likely in LA, since this is where most of the expatriate Persian community is (sort of like how Miami is the expat capital for Cubans).
Also, the Persian wedding fooding is usually catered by Persian restaurants or Persian catering businesses, so if that's good, then someone out there must be doing something right. :)
Personally, when I eat Persian food out, I stick with the kabobs, appetizers and salads, because I agree with you that grandma and mom do the homemade stews best. :)
Persian relatives from NoCal think Shamshiry (sp) in Glendale or Sheherzad (sp) in Westwood are the best LA has to offer. But agree w/ above poster - nothing in a commercial Persian rest. comes close to great homemade Persian food.
For kebab, Shiraz in Glendale
For tah dig, Shamshiri Grill in Westwood. They also bake their own fresh bread which is quite good
My favorite in the LA area has to be Javan. Great kabob, rice dishes, and tahdig (get half gheimeh, half ghormeh sabzi -- double the delicious!), and the ash-e-jo (thick barley soup) is flavorful, warming, cozy. I just wish they'd replace the cold lavash with some yummier bread.
If you're willing to step out a bit, the Green Cottage in Woodland Hills is exemplary. It's cozy and family-run, the portions are huge, and the quality seems to be a cut above the Westwood gaggle of kabob places. They also have delicious pickled garlic.
And I second the recommendation for Attari Sandwich Shop -- a sunny courtyard that offers a very different corner of the Iranian culinary landscape than the kabob shops.
And yep, make friends with an Iranian and have them take you home with them for dinner -- really the best bet.