You might also want to consider Chantrelle. I have not eaten there but the place is perpetually packed so they must be doing something right! Girardi's Osteria is also open Mondays. You do have some options.
Normally I would suggest Epulo Bistro, but they are closed on Mondays. You may want to try Demetris. They have tapas and a few Taverna Signature dishes, but they are not nearly as classy as Epulo. Good luck and happy birthday!