Once southern food was hard to find at restaurants north of the Mason-Dixon line. Now restaurants all over the country are serving grits, collard greens and waffles piled high with fried chicken. And at a strip mall in LA's Chinatown, Howlin' Rays is drawing crowds with boxes of bright paprika-colored, mouth-numbingly hot Nashville-style chicken. Jonathan Gold weighs in on why this hot chicken joint is worth the wait.