There are scores of Vietnamese restaurants dotted throughout Richardson and Garland just outside of the loop, and nearly all of them are poised to sell you the cheapest lunch you'll ever buy, in the form of banh mi. The sandwich is to Vietnam as pastrami sandwiches are to New York City and cheesesteaks are to Philadelphia, and they'll only set you back about three bucks apiece.
My favorite, for the next few weeks at least, is the version served at La Me in Dallas, located in the same strip mall as Vietnamese super restaurant Bistro B. La Me boasts a much small dining room, by comparison, and it's located next to a pet store, so there may or may not be a caged parakeet or two on the sidewalk out front.
Inside, the banh mi menu hangs over the counter, just to the right as you walk in the door. There are grilled pork options and sliced meat options and meatball options too. Look for versions that have "soft sausage" in the description, which is a goofy translation for the spreadable pate they use for most of the sandwiches. And when you order, don't forget to order extra pate and extra pickles.
Each sandwich gets slathered with butter, mayonnaise and pate before it's layered with your choice of toppings, heaped with tart and crunchy pickled daikon and carrots cut like french fries and wrapped in paper like a hoagie. It's the pickles and pate that make the sandwich, which is why you should order a little more of each -- the earthy, livery flavors get cut down by vinegar and sweetness that wash your palate clean again. And for three bucks you can afford to buy enough for the whole office, and they'll be received with a hell of a lot more enthusiasm than Jimmy John's.