My family (kids -3!)and I are spending one day in Paris this April. We are from the Minneapolis, USA and are staying in London but are taking the train to Paris for one overnight. We are staying near the Opera. Where should we eat? We obviously don't want anything frou-frou at all. But someplace where we can have bistro-type food and they will tolerate my well-beahaved kids. Also any recs for take-away type lunch?