"Whitefish salad is a necessity at traditional Jewish "appetizing" stores like Barney Greengrass and Russ & Daughters, which traditionally stock smoked and pickled fish, cheese, bagels and bialys, halvah and other small luxuries. According to strict kosher law, meat and dairy cannot be made in the same kitchen: Jewish butchers and delis traditionally supplied the meat, while appetizing stores sold dairy products. Fish can be paired with either. That's why you'll never see a Reuben sandwich at a truly authentic Jewish deli. Theo Peck, the owner of Peck's, a cafe in Brooklyn, is a trained chef and a descendant of the family that owned Ratner's, a famous Jewish restaurant on the Lower East Side. His version replaces mayonnaise with crème fraîche, and adds bright notes of capers and fresh herbs. Featured in: Everything New Is Old Again...."