Every holiday season, Nonna Carmela and her grandson John take a trip to Arthur Avenue in the Bronx to shop for ingredients for Christmas. One of their first stops is for fresh produce at Boiano Foods Inc. in the Arthur Avenue Retail Market. A cardoon is the thistle part of the artichoke plant, and it tends to resemble large claws of celery filled with strings that need to be peeled. “These are a lot of work,” Nonna Carmela says, “but every