I don't if anybody posted about this before(i did search,no result).
I've been a big fan of the lobster souffle at Orsay
(1057 Lex. 517-6400).This is a part of weekday lunch menu(i'm not sure about weekends),and you can get this with lunch pre fix which serves the salmon & goat cheese terrine(excellent!) for app,the lobster souffle for main,the Vanila/Tomatillo Dome(mousse cake,incredible!!don't miss!) for dessret.It costs $20,very reasonable.
Of course, the souffle is made to order,expect for 15 min.But the salmon & goat cheese terrine(may be with a glass of Chardonnay)makes you forget those 15 min.
The souffle is served with the bisque sauce(very tasty) on the side.Make a hole in the middle of super fluffy & piping hot souffle,and pour the sauce into it.
It's heavenly moment....
I know Paris can do better, but for 20 bucks and metro card,it's a great & fun experience.