two simple places in the neighborhood where we stayed in December - Forum Pizza - on Via San Giovanni di Laterano, first block s. from Coliseum - go through the empty looking front room to the big back room improbably good given the location - neapolitan pizza and other neapolitan dishes, servers may not be native italian speakers so communication may be a little rough - we stuck to pizza and some special lard-bread type item they proudly offered for Christmas - latter was wonderful - they do have some antipasti down front, but its not on the menu, so have to ask - a neighboring table of businessmen were eating a lavish portion of spaghetti with clam sauce.
PS the bakery right around there on the same street has good specimens of the standard breads of the Colli Romani, Genzano being the best, buyable in hunks and worth sampling.
Trattoria Luzzi also on Via San Giovanni Laterano at the corner of Via Celimontana (very near the Church of San Clemente) - a VERY simple, unpretentious, friendly and cheap neighborhood trattoria - typical roman pizza, simple pasta dishes, cicoria, etc. We saw an off-menu roasted fish go by one night that looked great, so look around and see what the regulars are getting.
Dont know, these might be totally overwhelmed in high tourist season, but still worth knowing about if that is where you land at suppertime.