Mark LoRusso clearly remembers celebrating the Feast of the Seven Fishes when he was young. “For people who grew up back East, in Italian-American families, Christmas Eve was always like no meat, lots of fish and pastas,” said LoRusso, executive chef of Costa di Mare at Wynn Las Vegas.

LoRusso’s is one of a number of Las Vegas restaurants, large and small, on and off the Strip, that are celebrating the tradition this year — some with prix-fixe menus, some a la carte, on only one night or for an extended period.