This isn't the place where the suits go to celebrate closing a big deal, or the restaurant everybody talks about down at the club. It is, in fact, something much better: Boston's oldest steakhouse and a Porter Square institution. Locals arrive by 9 Wednesday through Saturday so they can listen to performers such as Preacher Jack on keyboard while digging into a New York sizzler: an unadorned 14-ounce sirloin that arrives at the table sizzling, as advertised, in a cast-iron skillet. The marinated steak tips, prime rib, and seafood are every bit as terrific. Oh, and forget about the wine list: Just order a beer.