Thirty years is a long, good run for any restaurant, and so attention must be paid: Saturday, Oct. 12 marks three full decades for Nancy Longo’s Pierpoint in Fells Point. It was early 1989 when Longo bought the Emma Giles Tavern, a rowhouse-barroom at 1822 Aliceanna Street, with an ambition to turn it into a restaurant serving “Maryland cuisine with a contemporary style.” As her 30th anniversary approached, Sun columnist Dan Rodricks paid a visit for the Roughly Speaking podcast and recorded a conversation with Longo in the Pierpoint kitchen.In this episode: Secrets of a great crab cake. Plus, something new: The Crab Corn Coddie, a mashup of a classic crab cake and the Baltimore coddie, with some sweet corn added for crunch. It was Dan’s idea, developed at home, and he asked Longo to bring her expertise to the evolving recipe. The chef was game to give it a try. In fact, Longo liked the concept so much she plans to put the Crab Corn Coddie on Pierpoint’s menu as a special on Wednesday evening, Oct. 23.