When in Rome, one should be daring and try to eat something typical of the place-- But as I see you getting crazy to figure out which is the best restaurant where you can get your original Carbonara or your perplexity in front of a steaming bowl of tripe, here I propose you a tiny list with affordable, yummy snacks that will give you a flavour of the city and its tradition without stress!
I open this list with my favourite snack, the delicious supplì.
The etymology of the name seems to derive from the French "surprise", a reference to the filante mozzarella inside. This led to another "nickname" of the supplì, "on the phone": if the supplì is adequately hot, if you break it in the middle and separate the two halves, you should see the mozzarella getting ropy, making it look like the two halves are connected by a phone wire.
Places where you can eat delicious and cheap supplì are Re di Roma Pizza and I Supplì-- Both places are nicknamed "The House of Supplì" for a reason! Try both and pick your favourite!
Similar to the German krapfen, the difference is that eggs are not used for the recipe of those fried bits of joy.
Originally the bomba was a sweet to eat during Carnival (pretty much like the frappa), but in recent times it's possible to eat it all around the year.
The "original" filling is custard, but they can be found filled with nutella or jam too, or even in salty variants with mozzarella and ham.
The most popular place in Rome where you can get both bombe and ciambelle for a ridiculous price is the legendary Dolce Maniera: as this place is opened all around the clock, you may happen to see guys that right after devasting themselves at the disco with all kind of alcoholic crap, come here around 6 or 7 o'clock to "freshen up" with a bomba-- Things that happen only here in Rome.
Don't mistake it with the granita!
The granita is grinded frozen fruit juice, while the grattachecca is just sliced ice, flavoured with syrups and fresh fruit.
It's very simple and light, an excellent remedy for the scorching heat of Roman summers.
Grattachecche are sold in the area of Trastevere, along the riverside, in their specific and easily recognizable stands.
If you check Italian food blogs to figure out which one the best one you get tones of discording opinions, but you can go on a tour and try to visit all of them!
My personal pick is the stand of Sora Mirella if just for the splendid location by Cestius Bridge!
A very popular dessert is the coffee flavoured granita, the granita al caffè.
It's extremely refreshingh and energizing at the same time, and it's usually enriched with a generous amount of panna, whipped cream.
A place where you can eat a delicious, cheap one in an absurdly touristic area is the one that you can find at Tazza D'Oro, a shop specialized in coffee (no wonder it's nicknamed "The House of Coffee") located by the Pantheon, where you are sure that you can eat a "proper" granita of this kind.
So, as you see there are many snacks that you can eat in Rome, and that are strictly connected with Roman tradition, even if their place of origin is far from Rome, as in the case of the granita, which is a Sicilian specialty.
The most famous of those "immigrants" is probably the porchetta.
Even now, porchetta stands can be found on the streets during certain celebrations, like those dedicated to patron saints, but there are some rosticcerie and alimentari shops where you can find it all year around.
I'll tell you in advance, mistake it for kebap or consider it an "Italian variant" of it and you'll be promptly LYNCHED by the locals.
The porchetta is held as a culinary product of cultural relevance, and it's served and prepared with the same recipe since centuries.
In places like Er Buchetto you can savour it in a tipical Roman bread, the ciriola, and in alimentari like L'Antica Salumeria you can eat it as a filling for pizza bianca (don't call it focaccia!!), another peculiarity of Rome.
Every Italian region owns its peculiar variant of the "variety of fried fishes and vegetables", but the one popular in Rome and its province is the one that comes from the close-by region of Campania, focused on shrimps and squids.
The Paranza is a similar dish, but way more filling because of the (baby) fishes that come with it.
As a quick, tasty snack that you may eat even while walking around the streets, my suggestion is to make a stop to O'Cartoccio, where, besides the "classic" fritto featuring shrimps and squids, or squids only (my favourite), you can find and savour the cartoccio with fried veggies (I recommend the artichockes!) and the famous fried baccalà!
Take this list as a simple invitation to try and enjoy the street food of Rome, I hope it will serve as a starting point for your culinary adventure of personal discoveries!