For nearly 30 years, when you craved a fish-fry and a bit of Southern cooking, you could hurry over to Louisiana, or you could head to Catfish Corner, an unpretentious spot in the Central District. The thing to do: Ignore the occasionally surly service; order fried catfish, hushpuppies, cornbread, beans, rice and coleslaw; douse the whole thing in tartar sauce and hot sauce; wash it down with sweet tea; call it good.