Crispi 19, Rome
The traditional seven-fish meal served on Christmas Eve in parts of Italy (particularly in towns along the sea), gets its numeric significance from the seven sacraments. The type of seafood served usually changes based on what’s fresh. A list of Rome Christmas Eve traditional dinner venues. (List under construction)
Generally, in Rome you will find restaurants open on Christmas Eve and Christmas Day in the Jewish Getto and in all major hotels (an expensive option).*
Restorante Crispi 19 - between Spanish steps and Trevi fountain, an intimate and cosy restaurant. Service Christmas Day, New Year's Eve (nothing listed for New Year's Day) - Christmas Eve Traditiona 7 Fish Dinner menu/prices here - http://www.ristorantecrispi19.com/menu_vigilia_en.htm
New Year's Eve - La Rosetta (Via della Rosetta 8-9; 39-06-68-61-002; www.larosetta.com) may be the most famous notable seafood restaurant in the city. It is “a little touristy,” but solid and classic - only steps away from the Pantheon - very expensive - menu/prices on their website.