Yes, that site would be this one!
Off-menu dining specials have long been one of the ways casinos try to attract clientele, particularly locals, often offering dishes on which they just break even. These days, with chains having taken over the operation of a number of casino coffee shops, plus the closure of some of the old-school gourmet rooms, and the general economic malaise, these "secret" specials are thinner on the ground, or have been added to the regular menu, but there are still "secret" deals to be had for the savvy diner.
Here are the off-menu meals that we're aware of; if anyone's discovered others that we don't know about, please drop us a line and we'll add them as "updates" to this answer.
In addition, back in 2008 Mr Lucky's added a $9.99 all-you-can-eat prime rib off-menu special. This one's only served from 4 p.m. to 4 a.m. and comes with a choice of soup or salad, baked potato, and veggies.
Finally, there are also a couple of off-menu "graveyard" specials here, served from midnight to 8 a.m., including steak and eggs for $4.99 and a burger basket, which comes with fries, for $3.99, if you ask and show your player's card.
These are the principal ongoing off-menu specials that we're aware of that are served consistently to those in-the-know. In addition, you can sometimes get lucky at some of the old-school restaurants around town, where the chef might prepare something special if you ask. For example, Salvatore's at the Suncoast has the same owners as the former Fellini's, which was a true old-school Vegas joint, and we know from experience that the chef will pretty much make you whatever you want, if you don't find the perfect dish on the menu.
The cheap late-night deals served in many coffee shops and known as "Graveyard Specials" are more likely to be listed on the menu these days, but some dishes might not be, so it's worth asking your server if there's an unlisted deal. Click the link for the Graveyard Specials we're aware of. We update the list fairly regularly, but some specials are subject to frequent change, so call ahead to make sure a deal's still available before making a special journey somewhere.
One last thought is not for an off-menu item, but rather an "off-menu" restaurant, namely the venue known as "Secret Pizza" at The Cosmopolitan, whose celebrity patrons have included Justin Bieber and Selena Gomez. Here's what we wrote about this novel concept in the January, 2011 issue of the LVA newsletter:
Secret Pizza: (Cosmo)—Now this is clever. Among all of the great eateries at the Cosmopolitan, there’s a "hidden pizzeria." The place has neither a sign nor a name; you have to stumble into it on your own (the idea is to make it one of those undiscovered urban gems that only savvy locals and visitors know about). Once you find it, you still have to navigate the ordering process, since there’s no menu either. Actually, it’s easy. There’re three or four different pies to choose from. A slice of cheese is $3 and toppings are 50¢ extra. You can get a beer with your slice for $3.50, then pull up a seat (or stand) at the counter to eat. The whole experience is pretty cool, not to mention that the pizza is outstanding. With crisp crust, rich sauce, quality cheese, and tasty toppings, it’s reminiscent of Regina’s (out of Boston), which made a cameo at the Palms a few years back.
