An old Jew lives in an apartment building in an otherwise Catholic neighborhood where all adhere to the restriction of eating only fish on Fridays. Every Friday afternoon, however, the Jew bakes chicken for his Shabbos meal.
The tantalizing aroma week after week is too much for his Catholic neighbors. They convince the local priest to deliver an ultimatum to the Jew: either he convert to Catholicism and eat only fish on Fridays, or he has to move. The Jew agrees to convert. Three times the priest sprinkles holy water on him declaring: "Born a Jew, raised a Jew, now a Catholic."
The ex-Jew's first Friday night as a Catholic comes around -- and the perfume of baking chicken wafts through the neighborhood. A neighborhood mob charges into the old man's apartment demanding,
"What's with the chicken? You're a Catholic now!"
He says, pointing to the roaster on the table, "That's no chicken; that's a fish."
"Who are you kidding!" they protest. "It's a chicken!"
The ex-Jew walks over to the sink, wets his hands, approaches the table and sprinkles the chicken three times, saying, "Born a chicken, raised a chicken, now a fish!"