We would like recommendations of a moderately priced restaurant walking distance from the Opera Garnier for dinner after an evening performance.
Thanks for any suggestions.

I like Maceo on the rue des Petits Champs. It's owned by the same people who own Willi's Wine Bar, but the chefs are pure French.

See the web site for Le Grand Cafe, which is just off the Place de l'Opera on Blvd Capucines. Whether this fits your definition of moderate I can't say, but it is a marvelous restaurant.

Another vote for Le Grand Cafe!

The best Italian-style thin crust pizza I've ever had was at a pizza cafe (name eludes me) on Rue LaFayette about two blocks northeast of the Opera Garnier. It's a cheerful looking blue and white cafe (with Pizza in its title) on the north side of Rue LaFayette. Great pizza, great salads, great wines and quite reasonable.

Brasserie Flottes, 2 rue Cambon, near Place Madeleine. Good food, cozy atmosphere and the profiteroles! Mmmmmm.

I enjoyed the Cafe de le Paix... I sat there and let my imagination go...thinking of what that place and its atmosphere was like back "in the day"... I kept thinking of the movie GiGi...anyway, back down to earth now...
I'm chuckling coz I did eat nicely earlier...then I could just enjoy the pate, toast, some sort of confiture and wine!