I had mine with extra pickled jalapeños and it went particularly well with the sharp cheeses included in the sandwich. Their menu listed it as such: "baguette, beef bacon, mushroom, caramelized onions, monterey and cheddar cheese and gravy." The pickled jalapeños could be added at the customer's option.
A real sandwich is often defined such that when you're eating it, it's all over you. It was practically dripping all over me. Fastidious eaters may frown at the mess it makes but a true foodie would enjoy the experience.