I love their chicken sandwich.  I think the killer ingredient is the carmelized onions.  Jane makes some awesome quesadillas with carmelized onions.  The “Austin Grill” chicken sandwich is not on the menu but the people there know it by name. In case they forget, here are the ingredients:

Grilled Chicken
Monterrey Jack Cheese
Carmelized Onion
Lettuce
Tomatoe
Cooked Red Pepper
Chipotle Mayo
Toasted to melt the cheese.
Served with tortilla chips
Yummy!