We stayed in one of the Agriturismo places just outside Dorgali and were hoping to find a nice local restaurant. We didn't find many in Dorgali itself, although there are many in Cala Gonone a short distance away.
Fortunately, we stumbled upon Il Giardino and were delighted that we did. The food was of excellent quality, and very good value. The staff were welcoming, and were very accommodating (I am allergic to shellfish, so they adapted the menu slightly to suit - I wasn't necessarily expecting this, but thought I'd ask, and was very pleased with the result).
I definitely recommend the Tiramisu!
Our only regret is that we didn't find Il Giardino earlier in our holiday as we would have been back more frequently if we had.