Vietnamese food is both delicious & cheap in Silicon Valley. I would say it's authentic in San Jose, but I'm not qualified to judge how legit it is. Vietnamese food may not be as familiar as other cuisines in America, but it is one of the best comfort foods.

Pho (Beef Stock with Rice Noodles) - About $6 with satisfying broth and exotic cuts of beef http://www.yelp.com/biz/pho-tau-bay-san-jose

Banh Mi (Very Cheap French Baguettes Sandwiches) - No more than $3[1] and comes with your choice of meat http://www.yelp.com/search?find_desc=banh+mi&ns=1&fi...

[1] - Here in NYC, there is a dearth of good Vietnamese food. NYC Banh Mis are easily $6-8 for a subpar product. Contrast that to paying $2.50 in Milpitas for a giant Banh Mi.

Yummy, cheap, authentic Vnese restaurants in South Bay area. Since business is in our blood and everybody thinks they can cook, Vneses here are racing each other to open restaurants, the result is a ton of choices for quality and prices for us foodies. Yeah, I'm Vnese myself, and think that the quality of Vnese restaurants here are second to none, including inside Vietnam.

For business meetings and casual outings, try Vung Tau restaurant @downtown SJ or Paloma Cafe @Grand Century Mall on Story Road (try the beef stew there).

Really casual outings, try the food court of Grand Century Mall, chicken noodles by Pho Ga An Nam on Story Road (not on Google Maps! you got to ask a Vnese dude for directions! :) )

a little more upscale: Three Seasons @Palo Alto, Xanh @Mountain View.

btw, "pho" really is fast-food for Vnese like hamburger for Americans.

bonus: the best "French" bakeries are actually Vnese! For mouth-watering cake and desserts, try the bakeries in the Lion Plaza on Tully Road.