The morning market in Campo de' Fiori is the most central and photogenic of Rome's food markets — fruit, vegetables, flowers, and spices arranged around the statue of Giordano Bruno (burned alive here in 1600, as the inscription records). The market runs Monday to Saturday and is at its best before 9am.
The Campo itself transforms in the evening into one of Rome's most lively bar and restaurant squares, though the quality of the food on the square is variable. The surrounding streets — Via Giulia, Via dei Banchi Vecchi — are more interesting for independent shops. The nearby Roscioli is the best deli in Rome.