Il Pirata is the kind of trattoria that Tuscany does better than anywhere else: proper food, proper prices, proper atmosphere, no concessions to tourists. The menu runs to ribollita, pappardelle with wild boar, grilled meats, and a serious tiramisù. The wine list is short and sensible. Book ahead in the evenings; at lunch it fills quickly with locals.
The restaurant sits on a quiet street just inside the city walls, a few minutes' walk from the Castello dell'Imperatore. Service can be brusque in the Italian way that actually means they're paying attention to what matters.