i suggest to go to Belvedere (gps Jazzo Gattini parking) to see Matera from far. time is from 18:00 to night when lights on.
food: lamb and tomatoes. frie pizza with onions is for strong stomAch, otherwise avoid.
The Sassi were definitely beautiful, especially in the evening or at night. Coming here during Christmas time and you can see the nice holiday decorations, special markets, and a nice holiday vibe. weather was also great!