Last week, Matt Maroni unveiled a new dining option at MorSo (340 W Armitage Ave, 773-880-9280) called Off the Cuff: On Tuesday, Wednesday and Thursday nights, diners can put themselves in Maroni’s hands and get a dinner that’s entirely off-menu. Did this move mark the legitimization of what was previously a more underground trend? Perhaps. But plenty of secret off-menu items still exist around town. For instance, it’s hard to get ketchup on a burger at M Burger, but whisper that you want the “old fashioned” at any location, including the new one in the Thompson Center (100 W Randolph St, 312-578-1478), and you’ll get a burger topped with onion, tomato, lettuce, ketchup and mustard. Say “speculoos” to the folks at Edzo’s (1571 Sherman Ave, Evanston, 847-864-3396) and they’ll sell you a milkshake made with the obscure, spiced spread (say “the Elvis” and you’ll get a peanut-butter shake with chocolate and banana). And while the thrill of ordering off-menu is open to you at Three Aces (1321 W Taylor St, 312-243-1577), you may want to exercise caution: Ask for the “ghost face killah” and you’ll get a pizza (pictured) loaded with insanely hot ghost peppers, which, unlike the pizza itself, have no qualms about making their presence known.