Chef/restaurateur Mary Nguyen came to prominence with her elegant interpretations of Vietnamese cuisine, but her love of European cafe culture prompted her to open Olive & Finch, an all-day market serving breakfast, lunch and dinner in a casual, bustling atmosphere that encourages lingering and neighborly exchanges. The overall menu board is delicious and comforting, but it's the Greggers tongue sandwich that has us talking. The finicky cut, which can yield tough results in inexperienced hands, is cooked low and slow before being piled onto a crusty baguette with sweet caramelized onions and red peppers. A smear of tarragon aioli adds bright, herbal notes while a dab of roasted-garlic purée balances the mineral qualities of the tongue with rustic, earthy flavor. A cascade of arugula lends a fresh and bitter bite.