Nice restaurants around Marche Central for lunch
Try somewhere else :)
Nostos (Greek) is great food and price-wise, but maybe too casual for a date.
Senzala (Brazilian) maybe? I did not like it on it's former location, but I've heard more positive reviews since it moved on l'Acadie (but haven't tried myself).
Or if you have a car, drive to Fleury West (5 mins), where you can find Le Saint-Urbain or À Table, two neighbourhood bistros of much higher quality.