I've never been to Vietnam, so I wouldn't know. Considering the fact that the jungle fowl-- the ancient proto-chicken from which all others derive-- originated in Southeast Asia, the Vietnamese have been able to take their time perfecting chicken recipes. The one at Cordon Bleu is pretty damned good, but the best? I'll take their boast with a grain of salt. And a pinch of five spice.
Chinese Five Spice, if you didn't know, is a combination of ground cinnamon (cassia), star anise, cloves, Sichuan pepper, and fennel. When rubbed on chicken, it gives Cordon Bleu the means to pay its rent.

When I visit the place, it's usually before or after seeing a film at the Lumière Theatre, depending upon the subject matter. I'd much rather fill myself here than with movie theatre fare. And possibly for less money than a coke, some popcorn and a candy bar.
The food is-- I hesitate to use the word cheap-- inexpensive. I can stuff myself silly for $8.25 with the "Number Five", which I think is the most expensive thing on the menu.

The Number 5 consists of one piece of "five spiced roast chicken" which, apart from roasting, spent a good deal of time on the grill, one pork and glass noodle fried Imperial roll, one "shish kebab" (which is neither shish nor kebab. It's very thin slices of marinated steak. The only common ground it shares with kebab is that it is meat that spents a good amount of time over a hot grill), country salad (shredded cabbage), and "meat sauce on rice".
Meat sauce on rice. Ground pork, peppers, onions, tomato. It's piled high on nearly every plate. I'm fond of its no nonsense name. And its flavor. It's no surprise to me why SF Weekly dubbed Cordon Bleu the Best Dive Restaurant of 2006. It's good food. And damned cheap.

The next time you're in the neighborhood, whether it be to see an art film, catch a drag show, or pick up a hustler, stop by Cordon Bleu. That is, if you can get in.
Cordon Bleu Vietnamses Restaurant
1574 California Street (at Polk Street)
San Francisco, CA 94109-4708
Phone: (415) 673-5637
Hours: Tuesday- Saturday 11:30 am- 2:30 pm, 5-10 pm.
Sunday 4-10 pm
Cash Only. No alcohol is served, so bring your own beer. Hell, bring some for the women behind the counter. The last time I was there they said they could sure use one.