La Giostra

The chef/owner is Dimitri d'Asburgo Lorena, a Habsburg prince (with some local Medici blood for good measure) who opened this restaurant merely to indulge his love of cooking.

They start you off with a complimentary flute of spumante before you plunge into the tasty crostini misti and exquisite primi.
Among the more enlightened are ravioli di brie con carciofini Morelli (ravioli stuffed with brie and dressed with artichokes), and homemade taglierini with white truffles.

For an encore, try the nodino di vitella ai tartufi bianchi (veal slathered in eggy white truffle sauce with fresh truffle grated on top) or the lighter spianata alle erbe aromatiche di Maremma (a huge platter of spiced beef pounded flat and piled with a salad of rosemary sprigs, sage, and other herbs). Don't leave without sampling the sinfully rich Viennese Sachertorte, made from an old Habsburg family recipe.

This place has become (justifiably) popular, and even with a reservation there's often a short wait -- laudably, they don't rush anybody to empty up tables -- but it's worth it.