For years I had heard about the deliciousness of spicy Tunisian fish balls in a stew served over couscous from serious eaters like Jeffrey Steingarten, the former food columnist for Vogue. He told me that couscous de poisson was a specialty of the Tunisian Jews—possibly from the island of Djerba, where only a handful of Jews live today. A few years ago, I met Annie Berrebi, a Tunisian home cook living in Paris’ 16th arrondissement. She makes the dish weekly, either for Tuesday lunch or on Friday night for her family.Berrebi lived in Tunis until Tunisia’s independence from France in 1956, at which time she and her family came to live in Paris. At that time there were 130,000 Jews in Tunisia; today there are barely 1,300. But still, despite the political ups and downs in Tunis, her husband, Andre, travels back and forth to his native city, often bringing back harissa in his carry-on as well as his beloved merou, a kind of grouper, packed in ice.You will not regret making this dish (recipe here) for Friday night dinner or for a dinner party, and it’s perfect for Rosh Hashanah.