This post should be moved to the Air France forum as it does not regard all Flying Blue members.
Secondly, the a la carte meals can only be ordered when departing from paris and ton on the return flight.
I can not tell you about the quality of the a la carte meals on AF (onlu have KL a la carte experence) but the standard premium eco meals are not bad at all. I would only book a a la carte meal in Premium if I would make many flights in one period and would have had enough of the sandard meals. But thats my opinion.