If you are looking for the genuine local and traditional food, pick Trattoria del Moro-Aronne. The restaurant, situated near the Piazza del Popolo in Orvieto, is highly recommended by guide Michelin and a true favorite among locals (which is really a true reference).
The food is just simple and good: truffle or honey lasagna, stuffed chicken with truffle sauce, gnocchi al astice (light and delicious in a flavourful cream of lobster sauce), ossobuco with peas and tomatoes, truffle tartare, Abbacchio lamb, tiramisu or Catalan cream. All dishes are offered at a very good price and the owners accompany the whole by an excellent service. No doubt about it. More than worth the try.