We will stay at Hotel Il Cantico in area of Aurelio Sud. Need suggestions for non-touristy restaurants please, mid-range prices, nothing fancy/fussy.
You've asked the equivalent of How deep is the ocean?
Perhaps start with Trip Advisor's map of Rome's restaurants. If you hover on the purple dot, a box will tell you the name, rating, and price level.
https://www.tripadvisor.com/Restaurants-g187791-Rome_Lazio.html#MAPVIEW
I always find some incongruity in a tourist wanting a non-touristy restaurants. Rome is packed with tourists and they are everywhere.
Chat recommend the Ad Hoc restaurant enough. Fine dining, excellent prices and good prices