When Randall Restiano left Gramercy Tavern as beverage director to open a place of his own last year, his first instinct was to look somewhere in Manhattan. Then he ran the numbers. “The expense, return on investment, and volume of investors needed to make it a reality did not make sense,” he says. “I thought, Maybe it’s time to do something new.” Restiano took a space in the Westchester suburb of Bronxville with chef John Poiarkoff, another Union Square Hospitality Group alum, to open La Chitarra, a pasta bar and wine studio. “When I was deciding to do this, it was an emotional battle,” Restiano says. “I thought, Am I ready to give up the city? What does that mean for me?” The promise of lower blood pressure and lower costs was a tonic more powerful than his ego. “The amount of money you need to run a restaurant in Brooklyn or Manhattan at this point is so crazy. If you fail, the loss is massive,” he says.…