I happened along this food truck in the bayview. It's a real food truck - not one of those fancy hippie roach coaches. Junior makes a "brazillian burger" for the taxi drivers and tow truck drivers on and off shift in that area, and heading home. Looks like this has been happening since around 2010, and is listed in yelp and other sites.
The base burger is $10 and comes with a soda. No fries or chips. The burger is poor quality beef, but with everything under the sun on top - an egg, a pinapple, bacon, ham, lettuce, tomato.
I would say it's like an in-n-out with less grease and more taste. I'd like some more salt, a slightly higher quality meat. At $10 it's also more expensive, but an interesting counterpoint.
It's worth a stop if you're in the area and hungry. Apparently it gets going around 9 or so, and he's set up some movable benches. Junior's truck is a thing of beauty, with a short order grill wedged perfectly in the back of his vehicle.
98 Napoleon Street, corner of Evans