I was invited to lunch with my department and they chose Zinburger. It's my time to have some red meat, so I thought that sounded like a good enough idea. I spoke with the waitress about my issues and was assured that the beef burgers are only beef. For the seasoning, I gave her the list to check: soy, yeast, eggs, wheat, diary. The fries (ordered separately) are not gluten-free. I had a green ice tea and a mushroom burger with no bun, no cheese, and no mayo. I thought about getting a salad on the side, but their salads were pretty expensive, especially on top of a $14 burger.
The burger was fine, and I left full. But like my previous meal out this week, I was not really satisfied. If I were to go again, I would consider getting a salad instead of the burger. (For anyone who is not restricted, this place would be a calorie-fest; apparently, they have amazing milkshakes.)