At Passover, Mexican Jews eat what their ancestors ate: Polish Jews, of whom there are many among the 30,000 or so Jews living in Mexico City, eat gefilte fish. Those from Syria may eat fish with a green sauce made from romaine lettuce, green peppers, lime sauce, and other ingredients. Others, who have lived in Mexico for several generations, eat either Veracruz-style fish with a spicy sauce like my friend, Mexican cookbook writer Pati Jinich, or salmon ceviche with serrano peppers, as I enjoyed years ago in Mexico City.Ceviche is one of the oldest preparations of “cooking” fish in lime juice—first learned in ancient Persia, probably with lemon. Escabeche, another way of preparing fish—first marinating it in vinegar, and then frying it—is a distinctly Jewish notion that preceded ceviche. Jews who came to Mexico with Columbus and afterward brought the notion of escabeche with them, changing the vinegar to lime juice and adding the distinctly Mexican avocado, serrano chilies, tomatoes, and lots of fresh cilantro and oregano to the dish.I love the freshness of this dish (recipe here), and it’s perfect for the Passover Seder, served on a bed of greens, with matzo on the side instead of the usual cracker.*Like this article? Sign up for our Daily Digest to get Tablet magazine’s new content in your inbox each morning.