|Shroom Burger and Fries from Shake Shack|
The vegetarian option at Shake Shack is the Shroom Burger - a "crisp fried portabello filled with melted muenster and cheddar cheese, topped with lettuce, tomato and shack sauce." Anything fried is a little bit of a gamble for me allergy wise, but in the name of research (or in the name of me loving fried things) I was going to give it a try.
Portionwise, it's a little smaller than I expected. Also when I bit into the "burger," all of the cheese immediately oozed out, so keep it in the waxed paper wrapper. However, the taste was ok, and I had absolutely no allergic reaction whatsoever, which is practically miraculous when dealing with any kind of fried food. Also, the crinkle cut fries were very tasty, and reminded me of the Micro Magic Fries I enjoyed when I was a kid. So yes, while I try and healthy, oh, 75% of the time, it's nice to have a somewhat indulgent option every once in awhile, and I think I may have found it at Shake Shack.
Other nice tips about the menu. Allergen information is available for the "Top 8," and the same chart notes what's vegetarian and what's gluten free. There was soy in the Shroom Burger and fries, but clearly it wasn't a big amount. Also, you can get beer there (yay!). I have a number of friends who swear by the shakes, especially the peach pie shake (I got two electronic recommendations to try it immediately after my FourSquare check-in), but since I knew I'd be getting the Shroom Burger, I didn't want to overdo it with the dairy.
Eventually, I'll do a DC-area vegetarian burger place ranking, and Shake Shack will be on the list somewhere.