In the end, we ate at Kavod in the 8th arrondisement. Beautiful restaurant inside and fantastic, friendly, attentive service, reasonable wine list and a menu heavy on Foie Gras.

I ordered a coquelet and was a little disappointed, given the €29 price -- it was served without sauce or garniture, and the iceberg lettuce side salad at €6 wasn't great value either. On the other hand, my friends reported that their steaks were delicious, so maybe I just chose poorly (although I did order the coquelet on the waiter's recommendation).

In summary, if you need an up-market Kosher restaurant in Paris, Kavod's not bad -- but a better choice if you're on expenses than if you're paying out of your own pocket...