The "Mammer Jammer" sandwich at the restaurant of the same name defies description. Yes, it's essentially a cheesesteak: thinly sliced beef, cheese, onion, jalapeños and dried red-pepper flakes. But the heat from the chiles takes the sandwich to another place — or, rather, the endorphin rush brought on by a capsaicin overload takes you to another plane of existence, where you float on a crest of searing pleasure while your body tries to cool itself with a flop sweat. Consider that the "extra hot" "Mammer Jammer" ranks only fifth out of eight on the ascending scale of hotness. At the summit of that scale is the sandwich known only as "It." Trust us: You have to eat "It" to believe "It."