Specializing pays off here, had the some of the best supplì I've had. Every variation had its own special coating.
We were there at the end of the day and they'd sold out of the more tradtional ones, so we had cacio e pepe (sharp sheep cheese was a great addition), carbonara (creamy custard-like filling), and a daily special with tomato and chile flakes (least exciting of the batch). Also tried some great smoked potato croquettes and very eccentric fried baccalà, small pieces with very crunchy crust including some oats. The only dish we didn't like was some fried anchovy balls with sweet pickle.
Very friendly place, laid-back living-room-like atmosphere, great music (not too loud). Odd hours, noon-8pm (or later if the owner feels like it), closed Sundays.