I live in Orange County, and I live with an Omni that hates going to all-vegan restaurants. He does not like Veggie Grill or Native Foods. (sucks for me, those places are great)
He does love the pho at Loving Hut though.
Well crepe. I just wrote this huge thing about all these awesome vegan friendly Omni places in South Orange County, and I just realized you will be going to Escondito, and not coming this way.
If you can make it all the way to Escondido, I would recommend Stone Brewery.
http://www.stonebrew.com/AMAZING beer. Great location (it is actually IN Escondido), and the garden is really beautiful. We always eat out there.
And they have a vegetarian menu, and can very easily accomodate Vegans.
They even have a Tempeh Shepherdess Pie on the menu, which I am 99% sure is the recipe from Veganomicon.