Second the vote on Bistro Caraibes in Grand Case. Across the street was Ocean 82 with all their live lobster tanks, but I don't believe that place came back. If so, would highly recommend that place, too. Down the street a bit is the Rainbow Cafe and would recommend them as well, but not over my two top choices. Keep in mind that prices will be in euros on the french side. No biggie if using a credit card, but I would suggest checking to see if U.S. dollars are accepted on an even basis (though unlikely). If so, however, I would then pay in cash.