I often do ask the chef (often also owner) to recommend. Make sure you know the ingredients in case you are allergic to something.
But more importantly you should choose a restaurant that is not a tourist trap, as there are many of those near the main tourist sights. Inquire before you choose a restaurant.
Locals give the best advice. In the old days during my youth I relied a lot on construction workers for restaurant advice. That is a good strategy in rural areas, but in big cities like Rome nowadays 100% of them are Romanian or certainly non Italians, so I target different groups for advice:
1. College/high school Italian students. There are plenty congregating in front of schools and universities especially around 1:30pm when school day ends. Youngsters often eat in the city center so they know restaurants downtown. They are also likely to speak English.
2. Taxi drivers. They are definitely locals (citizenship is a requirement to have a taxi license and it is so hard to get one that those who have them transmit them from generation to generation and they are likely to be from the city itself). They are a good source of info. But make sure you don’t ask them at meal time. They will try to take you to a far away restaurant to collect some taxi fare from you.
3. Businessmen/women (bankers, lawyers, etc.) they frequently have work lunches at local downtown restaurants. Look for people dressed in a business suit and a business case.
4. Police officers, especially from the Municipal Police. They are definitely local and they know the restaurants downtown. They are the best source of information for bakeries where they make donuts. Police officers are the same all over the world. They love donuts. Once, when I was a teenager, I was chased at night by the Carabinieri on a hot pursuit on my motorcycle, not because I had done anything wrong as I thought, but because they saw me with my friends eating donuts and they wanted to know where we bought them.
Once you are in a reputable restaurant go ahead and seek advice from the chef. The only caveat is that some restaurants favored by locals may not have staff who speaks fluent English. That would definitely be a good sign.