As a rule, the concept of a "secret menu" should be regarded with healthy skepticism. They're essentially a ploy to get you to feel super-cool and in-the-know about ordering from things you don't see the price of, so you usually wind up paying extra for the warm feeling of superiority towards the sheep who think, say, a Double-Double is the end-all-and-be-all.
Throw that rule out the window when it comes to Ike's Place, which Thrillist recently revealed has an extensive secret menu, with some 50 additional sandwiches, most with the stoner-approved names like Cowboy Curtis (pastrami, homemade poppy seed coleslaw, BBQ sauce, and cheddar) or the "Christina & Umair Go to Ike's Place" (basically an Italian hero). There's no real rhyme or reason to it, and not all hidden things are available everywhere -- but the flagship Castro location has almost all of them. It's a democratic form of getting more out of life, way less douche-y than hacking into State Bird with a bot.
I got a John Connor, a massive and predictably wonderful angina-inducing combination of steak, habanero, mushrooms, avocado, and mozzarella sticks. It had great crunch and a perfect melt, and the employee who rang me up noted with approval, "You must come here a lot, ordering that." All told, it came to $15, which is borderline-obscene, but it was enormous (and you do get free chips).
If there's one area for improvement, sandwiches at Ike's tend to have a shade too much of their sauce, and by the time you're done tackling half of one, you can be left with a gloopy mess because the various layers have slid out of alignment. But that's the just price of adventure. And if you eat one and you're like, "OMG, Ike Shehadeh, I love you and I wanna have your babies," you can't, because he totally got married and invited all his employees to the wedding.
Ike's Place, 3489 16th St., 553-6888.