Honestly testaccio is where actual romans shop for groceries not just tourists taking photos. Open tuesday thursday saturday 7am-2pm near piramide metro station via galvani. Vendors actually know their stuff and prices are reasonable because locals would riot if they werent.

Moretti cheese stall has incredible pecorino romano aged in caves outside rome and the guy explains everything about aging process. Da bucatino next door does proper roman breakfast cornetti that put hotel pastries to shame. Felice bakery inside the market makes maritozzo with real whipped cream not the fake tourist stuff you get near pantheon.

Trust me the energy here is completely different from campo de fiori or other markets where vendors treat you like walking wallets. Also way less crowded so you can actually browse without getting elbowed by tour groups taking selfies with vegetables.

Pro tip go saturday morning around 9am when everything is freshest and vendors are in good moods. Also the monte testaccio hill next to market is literally made of ancient roman pottery shards which is pretty wild when you think about it.